Yes if you actually write software for desktop Linux you know that it's not that much of a problem to actually do it if you want to. There is enough free software available, you know often written by individuals without multi-million dollar budgets, that I have not had need for using a Windows machine other than to compile software for Windows machines. If multi-million dollar companies actually wanted to support Linux they could do it without breaking a sweat. The only reason they don't is because Windows user base is so large and Linux's is so small that the benefit does not justify the cost.

All you have to do is add a significant user base, say 5-10% of the market and it will be competitive with Mac and I am sure there will be lots more commercial software for it.

I would also like to mention that my sister is a total computer dummy. Her computer always gets infected with malware and lots of it. But I installed Linux on it because I did not have a Windows install disk. And she loves it because it doesn't get malware anymore. And she loves the fact that she can install free software using Ubuntu's software center. That's a true story.