Yeh, I sometimes think like this. I know it's not great for the whole "artistic integrity" thing, but there is something genuinely nice about producing something that someone is willing to pay actual money for, and that makes pandering to fandoms extremely attractive. Having said that, I seem to have already gained something of a following over on DeviantArt for drawing MLP comics, so I actually am seriously considering going to BUCK next year as a vendor.
But I'll need to have some of my own original stuff there, like "This is Normal" and "Not Quite Dead", because otherwise I feel like I'm selling out too much, and abandoning my own ideas, and that's something that really does nag at me. I love drawing things that get a reaction - but I always wonder how many of my current watchers will stick around once either the show ends or my ideas dry up. I'll probably think about it while rolling in cash in a Manchester hotel room next year.
Opratunity doesn't knock twice. If you see a way to make money, go for it.
Just don't lose yourself in the process.