Why? I have seen ideas/suggestions blown off for equally vapid reasons. Sometimes they just don't like me, and don't like that I suggested it, for whatever reason that is.
Are you seriously suggesting that since you didn't understand the reasons some of your ideas have been rejected, that it's fine to reject other people's ideas for any reason you like?
That's not what I'm saying at all. Let me give you an analogy:
"He got teased for being fat". I got teased all the time, why is being teased about being fat any different/special?"
I.e. I'm not saying it's "okay" to tease someone just because I question why being teased about being "fat" is any different to other kinds of teasing.
"It just is"? Seriously? You can't explain anything with "it just is", let alone a controversial subject.
I don't know what other kinds of vapid reasons the parent was referring to, but many are just as bad as "female". There's the obvious ones: racist, homophobic and transphobic justification for example, but also less common, also harmful vapid justifications. Dismissing someone's idea because theyre an ex-convict is a good example. Or on the basis of their age.
These are all quite bad, even if not completely equally so. I'd humor an argument that "female" is the worst of these simply because there are a lot more women than ex-convicts and members of a gender or sexuality minority, and therefore more people who could potentially be hurt.
Why should a reason of "female" be special?