Linus highlights several pain points with regards to desktop Linux.
From DebConf 14    • DebConf 14: QA with Linus Torvalds  

0:00 Application distribution is a huge PITA
2:52 Distros break things and ignore backwards compat.
5:53 Distros waste too much effort on package management
8:26 Linus roasts his own package maintainer
8:50 Windows has a better app distribution experience
9:29 Linux distros expect users to compile everything