Linux Complaints and Mass Market
Linux users complain a lot about their desktop environments. Gnome, KDE, Xfce, LXDE etc. But that's not nearly the biggest issue on the Linux desktop.
The biggest issue is the complexity of packaging software and the shear work required to create a distribution.
The end result is that not every distribution or version of distribution has access to a piece of software in binary form. People have to resort to compiling and packing their own software.
There should be a shift to fix package management, increase binary compatibility and delegate the work of packaging to the developers that create the software.
That means we can't have 20 different package managers. Distributions have to support multiple package formats without discrepancy. They have to be able to support previous packages somehow. Whether this means including dependencies from Fedora 14 inside of Fedora 17 to be able to run old packages or some other solution. It's a tough problem, but right now the state of software installation just isn't there yet.
People do not install operating systems for any reason other than to run applications. They will select the best operating system to run the applications they need.
Therefore, if the Linux community wants to gain mass market share, it has no choice, but to make it as easy as possible to create and distribute software for Linux distributions. This should be the primary concern, as there is little purpose for an operating system, other than to run applications.