I think that many times people feel left out and ignored in real life and they come here for someone to talk to and if they feel ignored here as well, then they feel lost and alone. Depression itself makes you feel isolation.
I do see your point and appreciate you taking time out of your day to post a helpful post about reasons why people may not respond to a post. That might help people understand other people's motives and to know that people aren't deliberately setting out to hurt them.