One significant difference between linux and windows/mac is the planning around features and the outreach. I work for a large organisation. The number of times a linux group has come round to our office to discuss what features are up-and-coming, or should be developed? None. The number of times Microsoft staff have done the same? Some.

Now I don't really expect linux volunteers to do this, but equally I don't really expect any linux distro to provide a coherent business desktop because they are not talking to their "customers" in the same way that their competition is. And the business desktop is a large market, if a bit unsexy.