I watch sports like football and basketball on one monitor while I game on another. I do the same with Twitch channels. I am interested you see...just not interested enough to focus all of my attention on it usually. Exceptions being "how to" or strategy videos. Obviously, gots to pay attention to those. Being able to ask or answer questions is nice in those cases. I have never really looked at it as social, but I guess technically it is.
I was slow to get into using Twitch but I have come to appreciate some of it's benefits. Madden was what pulled me into it and it has really helped to expand my game in a number of ways.