Just let me debunk some of your "facts".
First, the 5% you cited is for web developers - i.e. techies. If you look at the operating systems market share among average users, you'll notice that Linux has only about 1% (http://www.netmarketshare.com/operating-system-market-share.aspx?qprid=8). OSX has five times as much.
Second, writing applications for Android has nothing in common with programming for Linux - completely different environment, language, API etc - and so the developers group don't really overlap. Since you've demonstrated that you know nothing about portability between unix-like systems, you're probably not a programmer, but you could at least do some reading here.
Here's a homework for you: figure out how many pieces of software are there in the AppStore, how many are there in Debian, and then compare. And that's not mentioning the fact that in the last few years lots of Open Source developers replaced Linux with OSX, which is rather evident on Open Source-related conferences.