I think I tried Winamp back in the day but never really understood it.
One has to admit it’s good that they released the source code (while it was available) so users can learn what their software is actually doing on their computer. Better for yourself as a dev too: you will probably avoid including other people’s work in yours. However, wanting contributions while retaining the exclusive right to distribute the software is anti-collaborative. I’m reluctant to say it might as well be proprietary again but since it doesn’t meet the standard of software freedom then it’s equally not worth trying on my computer.
Not sure what I could have expected from it back then. I just recall it being recommended online and ended up just using Win Media player (with the cool graphical effects).