I agree, but the problem is how to avoid this. Once your livelihood depends on the thing you do for fun, it seems quite likely that you will start thinking abou

I agree, but the problem is how to avoid this. Once your livelihood depends on the thing you do for fun, it seems quite likely that you will start thinking about how to make it sell better. And after a while this may start to infect your inspiration... is your artistic integrity so strong that you can choose to do things that hurt your income? Of course the solution is to be financially independent already... but then you're not actually living off your art anyway.