I've used Linux as a Desktop exclusively from 1999 to circa 2008. When I finally gave up. I think it was Ubuntu releasing buggy PulseAudio which broke the sound for me that was the last straw.
I still use Linux as a desktop occasionally but I just don't have the patience to deal with the weird quirks anymore. And there were plenty of quirks over the years.
I never understood why Linux went with Windows inspired ctr-c and ctr-v. For me especially since I do most of my work in a terminal window it was always counter intuitive. Shift-Ins is problematic on laptop keyboards and even on full size keyboards it requires both hands.
Each year (or so it seems) Bryan Lunduke does a "Why Linux Sucks <year>"(http://www.youtube.com/watch?v=pSxX8a_TC7I) and I love it.