I had a whole speech ready for this but since I forgot most of it I'll just say I don't mind the lack of native themes for GNOME 3. I find that once you start modding how GNOME looks and runs, performance tends to start taking a hit.
I got really close to adopting KDE Plasma because of this, but then things began getting too cluttered because I can't stop modifying things. Eventually I got to the point that I just want something nice, simple, clean, and intuitive and GNOME has always been my go to Desktop, so I went back to GNOME.
I used to hate that about GNOME, but like I said, I tend to mod too much and end up hurting performance. To sum, I'm happy with the way it is, no it's not evil, it simply becomes problematic for people like me.