It's the raid mechanics ..... or more like the raid handicaps that cause this. It was far easier to teach someone raids in D1, because even on normal difficulty, if you died you could spectate the rest of the team until they could get you up or finish the encounter. Now, if someone dies, even on normal, you have a death wipe handicap mechanic and a token system where you can only rez someone once per attempt at each encounter. On prestige, not only do you lose your token for rezzing someone, but also the person who was rezzed. Then there is the puzzles and actual encounter mechanics. If you spend too long doing something because one or two people keep making mistakes that causes the wipe mechanic to kick in, you may have one or two others who just bail because they have been on 3 hour raids that could have taken 45 minutes and it gets old after a while. And lastly, you get people who are under-leveled wanting to go into raids / prestige raids. They get slaughtered within seconds time and time again just in the castelleum, and you have to tiptoe around them putting them in spots where they are easy to rez if needed and hopefully not take too much fire. But with this raid, EVERYONE has a role to play - no one can really be carried. When mechanics require all 6 people to function, that is a handicap of sorts. It's a great challenge for good teams, but not everyone fits that bill.