Well, the high level roulette is an exception. Mainly I think its not to force people to run them. They are after all old content, and they were 'enf content' once, so exp wasn't implanted, so why bother implanting it when you can add new dungeons. As for the old "Low Level" dungeons, well, they were implanted with EXP and still using since players still need to level up, plus why removing what is already implanted.

So its a fair thing, I feel bad about the high level roulettes that are abondoned after wasting a fair good amount of time. Add to that the importance of high level roulettes are lowered since they don't give the fresh Esoteric tomes and only Law tomes which can be obtained from other sources and are unlimited.