Your link does not support the idea that the term sexism means what the poster claimed it means. In fact, it contradicts it:

>Sexism is judging people by their sex when sex doesn’t matter

Did you even read that post? Not two sentences after the one you cite does Caroline Bird say:

> [Sexism and racism] have used to keep the powers that be in power.

A direct statement about the systemic, power imbalance nature of sexism. Sexism is both those individual instances of discrimination and the overall systemic and social issues that allow it to perpetuate.

>Did you even read that post?

Yes. I even understood it, which appears to be what's bothering you. The quotes you refer to, once again, does not support the claim. The statement "sexism has been used to do X" does not mean "the definition of sexism is X". Paint has been used to cover walls. That does not mean the definition of paint is "stuff that covers walls".