I get your point but then let's not complains if creativity dies and things all look the same. Creative people don't have motivation to produce if they can't make a living out of it.
This doesn't do much for the argument that artists only do art for money. Everyone knows what happens to free use art, same as what happens to FOSS: corpos bundle it up and sell it back to people.
By the way, I do know a lot of artists that just give their work away for free. Hell, any Burn is just a bunch of free art that usually gets lit on fire or destroyed after a week. There's also graffiti art which is uncompensated and usually painted over within a month.
> Would they do what they do if they had zero dollars?
No, probably not. Isn't it a shame we live in a world where we have the technology to automate all meaningful production, but people still need to justify their existence through often meaningless labor?
That said, I know artists that make the bare minimum to survive, on purpose, so they have more time to focus on art.
Yes, as long as they have enough to survive, people generally have some free time. I know someone who's living paycheck to paycheck and they make music as a hobby. Obviously, if you have to work 16 hours a day to survive they wouldn't do it – or at least they wouldn't have the capacity to share it.
"I'm not a capitalist, I am a creativist... Capitalists make things to make money, I like to make money to make things." - Eddie Izzard
It's more about the viability of making any kind of living from one's creative work, not motivation to create. (Though for creative works with large upfront costs, eg films, ROI motivation is relevant for backers.)