I have often wondered why musicians don't show up at gigs other than their own. I have concluded that time is an issue. As one thread poster said, if they're lucky, they're working that night themselves. Also, I don't know many full-time professionals, so the singers I know have day-jobs, family, practice times, etc.. One's days and nights can fill up pretty quickly.
I do get around to some music, but not as much as I would like. But I'm not gigging regularly (not trying to either), so I have some time. I know some people who do get to three or so shows every week, but I do not have the time.
I do find there is support if I reach out for it. My volunteer job at a local folk club keeps me in touch with others with similar interests.
I think each of us is responsible for creating our own community. Occasionally we luck out and fall into one, but most of the time we get what we get. So reach out. Hold a song group at your house or apartment. Ask someone to go to the show with you. Go out for beer or coffee afterwards. Just do it!
Roger in Baltimore