Maybe it's because we don't have a beginner section (which we will obviously vote "NO" for).
Remember we are in the 6-7% of the population using another OS then windows/OSX [source: http://en.m.wikipedia.org/wiki/Usage_sha...ng_systems]
Also we are in the 30-40% of those 7% that actually know how to use their system, which give us a statistic of 2-3% of the average internet user.

Anyway, it's also because we don't really know what to post or contribute with. (I've been giving up source codes that I've written but don't know what other thing I can write about.).
In a nutshell, it would be more simple if we can simply share daily experiences and problems we had (and some conversations we had on the IRC)