People always seem to put not wanting to play in a fireteam down to social anxiety. It's not that at all for me as I spend most of my working day talking to people I don't know so don't really want to do that when I'm 'relaxing'. If I had real life friends who played then yes I would play with them, but I don't so I play solo. I don't want to talk to randoms about whatever, the same reason I have never picked up the phone, dialed a random number and chatted about nothing to the person who answered. Destiny is a game so we should all be able to play as we want, but Bungie have gone even further down the 'fireteam' path (clans, nightfall timer, and two of the first three exotic quests requiring fireteams are examples of this) even though they said it was going to be more casual friendly.