i don't know what to tell you man. not everybody who develops open source projects for a living does it in their free time. for a lot of projects, particularly the big ones, there is full time development staff.

but i'm sorry, the thing you're describing, music performance being out of reach for everybody but the rich? uhh… that is how things are right now. lots of musicians are struggling to afford touring, even the very wealthy ones, and tours often don't do much more than break even. its gotten worse in recent years, too, as large corporations monopolize venue spaces and independent artists are pushed further and further into the margins. musicians have been talking about how much the live-music industry is fucked for a long time. its almost like the problems you're imagining would occur under a different system are exactly how it works under this one.