If I may add something, I noticed that roulette in general makes levelling experience through dungeons worse. When I levelled with my main, it was all low level people fighting their way the same, learning their class, learning the mechanics, and it was enjoyable. Sure, there also was the factor of game just launched and everybody being new that helped, but that's another thing. Fact is, a high level running a dungeon for roulette, only does it for the reward, and so tries to hurry the run, gets impatient and everything, not letting someone who's effectively attuned to that level enjoy it as it should be. I find it quite frustrating.
So I don't think the problem is for CM and PT only, but for any dungeon you have roulette people in. Just, the other dungeons had faseable queues alrady without it.