The psychological attraction towards retrofitting a formative experience of failure into an indicator of innate unique value does indeed seem irresistible. Which is a good reason to be suspicious of it; it's a meme that has evolved countermeasures to all of reason's defenses.

I did terribly in school, by the way.

Whether or not it's meant in 'sexist terms' doesn't make a sexist statement not sexist. Assigning such fundamental traits to an entire gender without a factual basis is pretty ridiculous.