I agree with you to a point. A raid which takes hours to complete would be a nightmare with just one person not pulling their weight. Another thing matchmaking would have a problem with would be quitters. Guys in a fireteam would be less likely to quit (Fallen SABRE Warsat springs to mind) My issue is that with optional matchmaking you could just opt out. Enjoy your raid with your fireteam. If your solo or if your fireteam were not in game, you could still play. No harm, no foul. If Kings Fall and Trials were off limits then why not add it to Nightfalls and the older raids. In the long run the more of us out there playing the game the better.