Due to today's festivities I don't have the time to rip this idiocy apart as much as I would like to. Let's just say that if you write an article titled "11 Horror Franchises That Should Have Stopped At 1", you probably shouldn't discuss sequels that by your own admission were often just as good as the original, and sometimes better. And yes, it should surprise no-one to learn that I'm talking about Romero's zombie films. OK, Land and Diary were both disappointments, but since the second two sequels and both re-makes are all brilliant, the series should really belong in an article called "11 Horror Franchises That Are Fucking Awesome But Went Tits Up Eventually, As Is The Way Of All Things". I grant you that it doesn't really scan, but precision is important in such things.
It's also worth nothing that the general fact that the number of a sequel is inversely proportional to the quality of the film isn't a property of horror franchises, it's a property of sequels. Not even just films, either, series of novels or comics are often afflicted by the same problem. Picking on horror (admittedly presumably because it's Halloween) seems more than a little odd.