As long as Bungie doesn't dumb down raids because the matchmade fireteams can't get it done, optional matchmaking is fine. But soon, oh how they would whine. "This one guy isn't doing anything and we can't keep going" "I got kicked for no reason :C" "This guy keeps throwing the raid encounters and wipes us" Not to mention that they'd have to implement a system that remembers your raid progress and only drops you into groups at that same checkpoint. Bitching would be soon to follow here as well: "Bungie, your game is shit, I have to wait forever to get matched, and I'm not even gonna acknowledge that that's because nobody is at that checkpoint, it's definitely your fault" I've seen enough matchmade activities in other games to see what's gonna happen. But hey, as long as raids don't suffer even more from it, why not. Might make for some funny failtages.