Yup, as much as I like Grayjay, I'm not going to help development much because it's "source available" instead of open source. There was an annoying bug I wanted fixed, and I was willing to go set up my dev environment and track it down, but they don't seem interested in contributions, so I won't make the effort.
Likewise for WinAmp. The main benefit to it being "source available" is that I can recompile it and researchers can look for bugs. That's it. They're not going to get developers interested.