You're missing context. The phrase is used in instances like this:
Person A: "Women have it rough. Patriarchy."
Person B: "No, see, [bad thing happened to this guy one time], so there's no possible way there's systemic bias against women."
Person A: "Yeah, _what about teh menz?_"
Feminists deeply care about men's issues. But they won't tolerate using specific instances of things being bad for men as a means to deny that there is systemic bias against women.
I think you're way off. The phrase could be used in such a way, but even in this thread the person to whom this insult was leveled against did not say "there's no possible way there's systemic bias against women" or deny anything about women or anything like it. The way you're using "context" is a hand-waving, straw person, red herring. You should check the context.
What, exactly, are these abstract phrases of which you speak? Does how the phrase actually gets used matter to you? Or do we all get to invent imaginary conversations for abstract phrases and lilly-white motivations for our (imaginary) protagonists? You accused someone of ignoring context but you're inventing it.
Context is important, but your point that the phrase can be easily misinterpreted is well taken.
The phrase should certainly not be used if someone merely complains about a problem that men have. Rather, it is intended to be used when someone tries to derail a discussion about prejudice against women by talking about how hard it is for men.
Note that the comment I was replying to was in a thread about education, and it immediately started trying to shift the discussion to suicide rates and the judicial system.
Person A: "Women have it rough. Patriarchy."
Person B: "No, see, [bad thing happened to this guy one time], so there's no possible way there's systemic bias against women."
Person A: "Yeah, _what about teh menz?_"
Feminists deeply care about men's issues. But they won't tolerate using specific instances of things being bad for men as a means to deny that there is systemic bias against women.