I would say it's more of a problem with society on a whole than just limited to DF. I was talking about this with my friends the other day in regards to XBL and how on the original Xbox people would always be talking with random people in games like Rainbow Six and I would get loads of friends requests from random people I just met in a game where we got chatting. During the 360 era and especially since the advent of party chat I hardly see anyone chatting and giving the usual banter. It's usually just people don't have mic plugged in or they are in party chat so it's very rare I will get a friends request from someone these days. People just don't seem to want to interact with strangers in games these days.