You are incorrect. You do not get to inspect my rationale for legitimacy.
You would have to actually present it, of course.
I'm not saying dislike isn't real, just that the rationales for it that tended to come to light in the course of the edition war were rarely based on anything legitimate. They depended on a straw man, an outright lie, ignorance, confirmation bias and other forms of factual error or flawed critical thinking.
Hey, but your rationale might be good. If you think it might be legitimate, you could share it.
The rest is subjective and I assure you, quite legitimate
Of course, there's no arguing /subjective/ 'reasons' for not liking something new & improved. Nostalgia, for instance, is a big one (it's why I'm more likely to play a 1e AD&D game at a convention than a 2e or 3e, even though the later are better systems, technically). You can prefer something in its 'classic' form without having to mis-represent it as somehow better than in a later form. No matter how much better the new version is on any number of objective criteria, the subjective opinion stands. For the one person with that opinion, of course.
Less understandably, you can just irrationally dislike any bit or quality of a system - from something far-reaching and positive, like game balance, to an annoying little detail like one anachronistic weapon out of dozens or an 'unrealistic' result in corner-case of skill check resolution, or whatever else whinges you out - and let that spoil the whole for you.
Subjective reactions like that happen with every rev-roll, and every rev-roll does have hold-outs who just won't accept it, as a consequence.
Every rev-roll didn't give those hold-outs a Pathfinder to buy, though. Nor promise software it couldn't deliver. Nor have to pull down double the sales of the entire industry to meet the low end of it's revenue goals.
Those things are important, and so far unique, parts of the '4e experience' that the OP asked about. The obligatory nerdrage over every rev-roll is less so.