If the next part is more interesting, how are people who aren't slogging through Eureka by taking the forums advice ("if you don't like it, don't do the optional content") going to get to the interesting part? They'll have to then slog through the boring grind, only there won't be the other people in there now to drive it along because they'll be done. The level power scaling in Eureka is so absurd that playing with people 10 levels away from you doesn't work at all, and there isn't exactly an abundance of low levels floating around now.
The old relics made people go back and do old content to avert that. Eureka... doesn't do that.