I know what you mean. It's not ideal and it's a choice of convenience but I decided I wanted to be part of the world again after a few years of kind of sort of not, and I went where the people are. I don't like that I can't read the source, but on the ux alone it's an upgrade over IRC and Skype in both of these niches for me.
It's fuzzy for me too. In my head it's "all those people I used to talk to in IRC" but naming names is more difficult.