The downside to this approach is that it can kill the passion for the thing you were passionate about. Also, I've noticed that real world solutions to problems

The downside to this approach is that it can kill the passion for the thing you were passionate about. Also, I've noticed that real world solutions to problems tend to include lots of schleps that are excruciatingly boring, but necessary. The longer I do this kind of work, the more strongly I believe that the people who are most likely to see a project through to completion are the ones who have the stone cold professionalism - or just plain stubbornness - to grind though the boring stuff instead of just faffing around on the bits of the problem that they're passionate about. I think a side project that's just about indulging a passion is totally fine. But a side project that is also a product that makes money will almost require lots of pieces that definitely feel like work.