Imagine how much content would be created if they were getting paid. Easily ten times if not a hundred times as much.

Do you realize the motivation behind that work? It's not Recognition even. It's certainly not money.
Do you know how much art is created and posted for free, to deviantart?
Do you realize how many tutorials, guides etc exist, for free?

You think that people are doing that because they want money? They hardly care for recognition even, many do it for something else than "thumbs up".

You imagine things that have not manifested despite the fact that there's a plethora of ways to patron those people. What happens when the people who did it for free get paid? Do you really think that money means they will pump out more, or less? Would it be hard to imagine that its usually less?

You know what motivated people more than money?