Because you are used to it. It would've been the other way around if you grew up with macOS. I have no problem with both of these systems after spending the time to get used to how macOS behaves. Hated it at first too after being "forced" to use it at work because I wanted to use it like Windows.
But I still feel bad about using it even though I have been using it as primary for 10 years now.
All the little details annoy me, like the animations, settings, mouse acceleration, etc, etc.
I know some animations can be turned off, some things can be tweaked, but this is also annoying.
I haven't ever seen as cheesy animations as the genie or the annoying jumping icon.
Spotlight search rarely giving me the results I want, then at last moment when I'm going to pick something, changing the results, etc.
And in general the toolbar design I don't like at all, I still can't reliably feel it out when the toolbar should pop up from the bottom when not, and then all the windows are kind of positioned in a messed up way due to that, either having a weird gap below when the toolbar is not visible.
Because you are used to it. It would've been the other way around if you grew up with macOS. I have no problem with both of these systems after spending the time to get used to how macOS behaves. Hated it at first too after being "forced" to use it at work because I wanted to use it like Windows.