hmmm yeah. But after the slave revolt, they are all like... "are you still here?". No while you collect nice fingers and karma killing the raiders, you've left the Pitt in an unstable/potentially worse situation overall. Helping the Raiders (and killing a few slaves) doesn't feel right, but ultimately it's the only course of action that makes sense (in a "I'm the saviour of the Wasteland" kind of way)

He seemed to be interested to me...when you tell him about Vault 87 then ask him if he has any insight about the mutants he cracks that you've learned more about them in the few weeks you have been out of the Vault than they had in the last twenty years so perhaps they should be asking you that question. The War with the Enclave was the bigger concern at the time. During BS the Brotherhood does establish a presence in that area for the first time by driving Talon Company out of thier HQ at Fort Bannister (well, OK...watching you do it.). Leading the Scourge of Vault 87 would have been a good DLC....breaking the back of the mutant threat would give the BOS precious breathing room to rebuild thier numbers (and properly train thier recruits) and consolidate thier victories.

That's my point. All that is one big assumption, we don't have any proof of anything of the like happening. Ever.

the G.E.C.K. makes everything happen

It's certainly more plausible than the idea the Enclave was ever going to help anyone but themselves, in spite of all the evidence to the contrary.