Well, there was no chance I wasn't going to have some fun with this: Spencer Ackerman's argument for why the Battle of Hoth makes even the Battle of Endor look good for the Imperials.
I'm sorry, but Ackerman is all kinds of wrong here. Wrong in how he analyses the encounter on Hoth, and wrong in how he implies it was somehow a worse performance than was seen on Endor soon after.
And now, like a Dagobah swamp-monster, let's get into the weeds.
First up, there's the matter of misinterpreting poor old Admiral Ozzel:
[The] bumbling fleet admiral leaves hyperspace too close to Hoth, losing the element of surprise and allowing the Rebels to activate the shield.Surprise was not lost by this manoeuvre; it was guaranteed. Indeed, this is stated on screen, Ozzel "thought that surprise was wiser". It's never made clear why Vader wanted the fleet further from the system, but the most likely scenario I can come up with is that Vader wanted time to create a much larger and deeper blockade by seeding Star Destroyers in nearby systems and in deep space, allowing them to create a stronger net that would preclude possibility of escape.
This would surprise the Rebels to, at some point, but the risk with this strategy is obvious: blockading an entire planet is likely to be very hard (depending on whether there are technological solutions not shown on screen, of course). Blockading an entire system would be quite literally astronomically difficult, and if the Rebels find out what you're doing halfway through, they might be able to punch out en masse through the half-assembled net.
Given how bad the Imperials repeatedly demonstrate themselves to be at keeping secrets (the Death Star plans, the Emperor's whereabouts being uncovered by a bunch of walking Alsatians who nonetheless are apparently excellent spies ), I'd hesitate to suggest he made the wrong call (well, it was clearly wrong for him, but...).
Alas, Vader’s plans are at odds with each other. Vader jumps into the Hoth system with a handful of Star Destroyers; only six are shown on screen. That’s got to enforce a blockade of an entire planet. His major ally is the Rebel energy shield itself, which bottles up a Rebel escape to the Ion Cannon’s line of sight. But Vader doesn’t seem to realize the shield’s ironic value. Once Vader orders the shields destroyed, he lacks the force to prevent a pell-mell Rebel retreat.This is partially true, though I'd be inclined to ignore the fact that only six Star Destroyers are shown on screen, just as I doubt there were only five X-Wings in the fleet that took out the second Death Star. Also, it's not the shield that's the problem here, it's a) the fact that the Rebels only have one base, and b) they only seem to have one ion cannon. The ion cannon will still be there once the shield is down, and the ships will still be leaving from the same comparatively small geographical area, there's absolutely no evidence that the shield itself is impeding where the evacuation is coming from, merely how often ships can leave (and even that may not be a limitation so much as the speed with which each transport can be made ready).
In fact, the Rebels plan is very clever: use an ion cannon that can't be hit to prevent any ship from intercepting leaving transports. This is quite possibly why they only have a single base in the first place. Of course, in doing so, the Rebels have pretty much guaranteed that once the ion cannon goes dark, they're utterly screwed. Even if the Imperials do have only six Star Destroyers in orbit, it's exceptionally difficult to believe that they - and their attendant swarms of TIE fighters and bombers - couldn't blast the entire evacuation fleet out of the sky; particularly since the Rebel base has a clear lack of intercept craft available (possibly because all their pilots are getting shot to pieces trying to trip Imperial Walkers up in the snow).
In short, disabling the shield is less important than disabling the ion cannon, and it's this that strikes me as the obvious flaw in General Veers' attack plan.
A smarter plan would have been to launch TIE fighters against Echo Base — since aircraft and spacecraft can get past that Rebel enemy shield — to lure the Rebels into an evacuation from Hoth through their shield’s chokepoint. Concentrating the Imperial Star Destroyers there would lead the Rebellion into a massacre. At the very least, Vader has to sacrifice the ground-assault team entrusted with bringing down the generator powering the Rebel shield for a laser bombardment from the Star Destroyers.Oh dear boy, no. Apparently plenty of people wrote in to point out there's nothing in the films to suggest TIE fighters are atmosphere-capable, but that's not close to the biggest problem here. We know Rebel spacecraft can get past the shield, in much the same way I can get past my locked front door, but there's no reason to assume this extends to Imperials, and several reasons to believe it can't - the most important being common sense; there's not much benefit to a shield that can't stop a TIE fighter falling to Earth with a nuke attached. Even if we granted Ackerman his horribly shaky premise, it doesn't change the fact that the "choke point" idea once again requires the ion cannon to be offline.
Ackerman is on firmer ground (no pun intended) as regards the battle on the surface. It does indeed seem like an oversight that the Imperials choose to send the AT-ATs in without air cover; one would assume it wouldn't be too difficult to drag speeder vehicles inside the shield and then start them up, though in truth the Imperials might have gotten through entirely unscathed if there hadn't been a Jedi in the field, and if AT-AT commanders had been trained to use an emergency brake. It's also difficult to see how Ackerman has concluded it was the full retreat that allowed the AT-ATs the opportunity to destroy the shield generator, as oppose to their almost entirely unimpeded assault through the smoking wrecks of Rogue Squadron finally bringing them in range.
That said, I do agree that the Imperials made a mistake here. They should never have been aiming for the shield generator at all; they should have been aiming for the ion cannon. The shield itself does the Rebels no good if it they can't evacuate, and the evacuation is not aided in any way by the shield alone. I'm not sure if Ackeman's diagram of the ground assault is canonical - it may have been that the ion cannon was harder to get to than the shield, so the Imperials chose to destroy the generator with the AT-ATs so as to leave the ion cannon open to orbital bombardment - but if we assume it is, that's an opportunity missed.
All of that assumes, however, that Vader's overriding concern is the crushing of the Rebel Alliance, which frankly makes me wonder if he's watched the original trilogy at all. Empire is very clear on one thing; Vader has worked out who Skywalker is, and is determined to acquire him. This is not a goal that is likely to be accomplished by carpet bombing Hoth. He'd have a much better chance of finding Skywalker if he himself lands on Hoth, hoping to draw Skywalker - surely in the middle of the battle to save his friends - and either draw him out there and then, or gain some high-level hostages he can use for leverage later.
Which, obviously, is exactly what he tries. Capturing Skywalker in space is desperately unlikely; Vader has, as Ackerman notes, learned exactly how good a pilot his son has become. And if maximising his chances of capturing his son means giving up on blasting the rebel base from space - a result that probably strikes Vader as unlikely to lead to acquiring captives who can be tortured for information, to say nothing of uncomfortably close to Moff Tarkin's last ever battle plan - then that's exactly what's going to happen.
So, no. The battle of Hoth was not in any way a terrible performance by the Empire. It began with a risky but by no means indefensible choice for a surprise attack, continued with a ruthlessly logical ground assault, and concluded with a tactical choice that placed intelligence and strategic concerns (Luke as a Dark Jedi ends the galactic civil war immediately, pretty much) over the narrow tactical victory of minimising the success of the Rebel evacuation.
Compare this with the total defeat at Endor, in a situation where air support was readily available, anti-personnel devices were seemingly utterly forgotten, a rigorous program of defoliating the area around the base was never even attempted, and the scouts used as an early warning system were given the most horrifyingly dangerous forms of transport imaginable in deeply forested terrain. I don't thiunk it's hard to work out which encounter represents the true debacle.
 And before anyone says it, yes, I know that info was fed to the Bothans. But the fact no-one apparently considered the possibility that the data was deliberately leaked suggests there's good reason to assume Imperial incompetence regarding security protocols.