It's one thing to be reticent about actively raiding, or to think that Warlocks should concentrate more on Scions. I'd certainly prefer that the cabal stick together in facing any enemy, including Battle and Sylvan, but that's not something that will get someone tossed out.

I can and will toss out any warlock I see knowingly giving aid to one of the cabal's enemies, though. The Cabal has to come first, and when you start putting the needs of its enemies above your fellow cabal members, then you shouldn't be in the cabal.