An attitude of "only class matters, shut up about feminism or queer liberation or whatever" is detrimental to said collaboration.

True, but I'm not interested in collaborating with online "activists", especially if they jump into my mentions on an unrelated topic for a bit of sealioning. At that point they're fair game for trolling, and telling them that their concerns mean no more to me than mine do to them is both true, and a generally reliable tactic.