2. UI\UX is lacking. Too many controls all over the place or at least too sticking out.
PS: "all over the place" is just the best phrase I can thing of in english to describe KDE. But most of all this is just about two different views on how a DE should look and feel like.
KDE fans prefer this "I have all the inputs in one place even if I use 80% of them once a year" and "I can configure every pixel even though I won't do it ever".
Gnome fans prefer "clean and simple (and opinionated)" and "this DE gives me 80% of what I can possibly want for 20% of effort".