Blu is exactly why other jobs don't have CC options or instant death. It makes some content trivial. It also makes those job far more desired than others. Nin can now instant KO any single lesser enemy on a 90 second cooldown. Why bring a Drg when you can bring 4-5 Nin that do effectively 10x the DPS when you consider they eliminate enemies other job have to damage down?

I enjoy Blu a lot. I think they should be allowed in roulette for old content like alliance raid and main story; but I understand why they're not at 80 or allowed in certain content.