Some open source projects are easier to work on than others. If it’s a bug in Firefox that I want fixed, no way in hell am I going to do it. But for a relatively small app or library that is easy to build and has a reasonably understandable codebase… I’ve found the DIY option to be very satisfying. Even if I have no way to contribute my improvements back, at least I can still reap the benefits.
I understand that people who release their code have zero obligation to do anything beyond that. It’s their code, their lives, they can do what they want. There’s nothing wrong with that.