VLC can do many neat things, but I never, ever saw it as a replacement for Winamp. It's more like a toolkit, or at least the multi-tool you fall back on to do a variety of things.
Who rates MP3 files?
I don't have any demographic information to share. But I personally attempt to rate my files. It gives a nice way to categorize by quality. That way I can have abjectly terrible music in my collection, but filter it out for the purposes of not ever wanting to listen to it.