I find this quite a serious subject in a way. It reminds me of the long journey people like me, starting as you did back then without anyone to help you, make to become "musical";
you are drawn to the music because of the guitar's sound. Your aim is to manage to reproduce some of the things you hear. There might be no thought of performing a song alone for many years; you will probably sing as you play, but only in your head.
      Some are happy to stay that way because of the satisfaction obtained by fingering a riff that's taken them ages to master. Indeed, they might not even have "rated" singing as something worthwhile. They are essentially accompanists at heart. Just out of place in the context of a singaround.