Desktop Linux has been a little bit of a fragmented landscape over time, but I think that what keeps most organizations using Microsoft is that they have someone on staff dedicated to resolving all of these problems for all their users. Most organizations don't ask their regular employees to do things related to setting up software, making sure that they have access to network shares, etc, that's done by a dedicated IT staff that just happens to only be Windows right now for some reason.

Over time the web browser is becoming the only real software that is needed and that has simplified things.

Gaming has helped improve the Desktop Linux space, and Valve is a great force for change there. KDE has decent funding and adoption now.