For those transitioning from Pathfinder 1 to Pathfinder 2 a potential reason to dislike it for those who dislike it is you have to pay for things you used to get for free. In Pathfinder getting a level in a class or being a particular race just means poof now you can do something. In Pathfinder 2 you have to choose to select it by paying a feat. You get feats every level but depending on level can only use the feat for particular things. One level is for a class ability while another level is for skill use. Racial abilities are nerf hit hard with this. You do not get everything a race had in the beginning. You have to spend a feat at a later level for what you used to get at character creation.

I think I understand why they did it this way. The whole of character creation and leveling is the archetype system to be as customizable as possible. I haven't played it to give an informed opinion on how well it works, but I can say it makes the game quite complex. 5E probably spoiled customers in its simplicity of creating a character and leveling. You have choices, but they're limited. Pathfinder 2 makes Pathfinder 1 character creation look like a first grade reader. Complexity is not inherently a bad thing, but tastes will vary.