but there's a reason why stereotypes exist 
I thought that reason was ignorance?Oh, come on.
Tell us why few women are here. If women are equal to men in every way, then WHY aren't they represented equally on this forum?
Is the big bad European white male keeping them off forum.bitcoin.org? I doubt it.
Obviously there are gender differences that go beyond "plumbing". To deny that is to deny reality.
He's right -- stereotypes exist because they're true 90% of the time. Plain and simple.
If I started stereotyping Americans as people that like to drive their cars into trees, the stereotype would die pretty quickly because A) it's stupid B) it has no basis in reality.
So it wouldn't catch on.