Some of us do. The hobby may consist of simulating the professional experience, but to a limited extent and on our own terms. For instance in my own case, I play an instrument -- the double bass -- and I perform sporadically. When I practice at home, I'm aware of the qualifications and competency of a professional bassist, I measure myself against those standards, and try to keep improving.
This doesn't detract from the pleasure of playing, at all. If anything, it gives me some structure and motivation. And I still don't mind noodling for a while when I need a distraction that doesn't involve a screen.
But I only count the money that I make, because I have to report it. ;-)