Eureka is the issue in this case, not BLU.
Eureka was farmed and complained about by players to no end who felt like it was forced on them because of the relic gear. Forcing people to go back for BLU would be a horrible move.
Eureka is dull & boring.
Killing X mobs to spawn a boss, then killing the boss isn't interesting or fun content.
BLU is also suppose to be solo content, but I guess we can already throw that out the window.
