"They were so pathetic. I felt terribly sorry for them."
Don't waste your energy. They neither seek nor welcome your sympathy.
"It was like they didn't belong anywhere, and getting sick would bring them into a community or something."
It is for them a part of the homosexual("gay") identity.(Thereby putting the lie to the claim that "AIDS is not a gay illness.")
"They would get some attention and be cared about."
Not by you. Only by their fellow disease vectors.
Sorry, but these organisms live in a different world than normal people. You don't have a clue about them. I have a glimmer only because I have worked with them off and on for years...
I suspect you are right, I really don't know much about them. I just felt sorry for the ones I saw interviewed. There must be some hope for them, though. Many do come out of that lifestyle, by the grace of God.