I used to play WoW with 40-man raids. There were strategies to EVERY boss fight that required people to perform certain duties during the boss fights. The random factor takes out a lot of the strategy for the Atheon fight. Yes it's an easy enough fight if everybody does their job, but when people start messing up because they aren't used to doing something, then it makes the fight a lot harder. Bungie's entire argument against matchmaking is that it wants raids to require teamwork to complete these raids. Then when teams build solid strategies for these fights they come back and say "wait a minute, you guys developed too good of a strategy for this fight, so we are going to screw with the mechanics of the fight so your strategy goes out the window". So Bungie is in fact contradicting themselves with this change.