I realize I'm probably wasting my time here, since all this amounts to is just "lets band under the positivity banner", but if you actually wanna know "Why all the hate?", I can give a rundown of the general issues.
Sure, Crit is diffcult, but much of it is artificial. People weren't asking for crit just because they wanted a challenge, that's part of it, but what was always the most important was making meaningful decisions. If a game is too easy like KH3 Proud is, none of your decisions are meaningful because there is literally zero tension in everything. Crit certainly helps, but it swings way past the sweet spot to the other end of the spectrum: So few options are safe and viable, that it turns into a boring campy slog or you just die randomly trying to do anything else. People talk about Darkside murdering people as some kind of great achievement of KH3 crit, but really, Darkside isn't killing people because of some genius design, he's killing people because it's a shitty boss, just now with inflated damage.
If that wan't bad enough, many of the changes to crit reduce the amount of meaningful decisions you can do. Less MP does fix fire spam, but it also means less magic in general, less decision making. Disabling attractions is the most boring way to "fix" them. All it does is remove a game mechanic, reducing the depth of the game, not increasing it. Less situation commands once again means less options, less decisions. Sure, all of these make the game harder but they don't make it more engaging.
Nevermind that many of the complaints people had remain unadressed. The game is still balanced to hell, just now instead of Fire spam you move down the list to Link spam. At least previously there was a decision to be made between spells and links, but since links don't care about how much MP you have, only that it's full, this choice becomes a no-brainer. Damage scaling is still atrocious, leading to chip damage without insane amounts of micromanagement if you want to do a low level playthrough. Food is still a stupid mechanic because it amounts to just stat boosts most of the time, in which case they might as well just increase your base stats and remove the hassle. It adds nothing to the game, at least Monster Hunter provides actually meaningful and interesting buffs with it and even FFXV made it a core part of the gameplay loop with camping. KH3's is the most boring and barebones way you could possibly implement this system. Kupo Coin still exists even though it goes against the very point of Crit mode (though at least it got nerfed, thank god). Most formchanges are still interchangeable braindead AoE damage, even when they aren't reskins of oneanother (with maybe like 3 exceptions: The blasters, the shields and mirage staff).
Crit is certainly much better than Proud. Credit where it's due, Critical Counter and Critical charger (or whatever it's called) are good additions to the game. Now that it's out I will never touch the lower difficulties again, but it didn't suddenly turn KH3's shallow combat system into anything more than that. It used to be shallow and easy, now it's just shallow and hard.