Your understanding is incorrect. As several other comments in that thread point out, "This is a viewpoint of some feminists, but it is
far from consensus, and the first three users of the word “sexism” appear to have disagreed with the writer" and "By claiming the term ‘sexism’ exclusively for acts against women, aren’t we disenfranchising the men who also suffer?."
There's even the complaint that the given definition is inappropriate for a Feminism 101 definition, saying "If I had no prior knowledge of feminist theory or the contentions that really _abound_ in the rather amorphous field of feminist theory, I would take what has been presented here as established fact rather than a specific argument and one of many hypotheses on the matter of “what sexism is.”"
I just this evening read a few chapters of the excellent "A Law of Her Own: The Reasonable Woman As a Measure of Man", by Caroline A. Forell, Donna Meredith Matthews. I think you'll agree with me that it's written with a feminist voice. Page 72 starts its discussion on female-on-male harassment in the workplace. They give the example of Richard Williams v. Runyon where Williams' supervisor, Clora Grant, was the alleged harasser. The court decided that it wasn't harassment. I read the court decision, and I agree with the authors of "A Law of Her Own" - the court was wrong and it was clearly harassment.
Which means I easily found an example of feminist legal scholarship which was using the same definitional premise you quoted as applying to all feminists.
I assert that it's much more likely that that quote is wrong than that Forell and Matthews do not understand feminism.
BTW, the interpretation of Title VII has changed since 1995. That's why now there can be a decision like:
> DETROIT – LensCrafters, a major eyewear company, will pay $192,500 to settle a female-on-male sexual harassment lawsuit filed by the U.S. Equal Employment Opportunity Commission (EEOC), the agency announced today. The EEOC had charged that LensCrafters subjected a male employee to a sexually hostile work environment at its Saginaw, Mich., retail location.
> According to the EEOC’s suit (Civil Action No. 1:09-CV-12694, filed in U.S. District Court for the Eastern District of Michigan), LensCrafters violated Title VII of the Civil Rights Act of 1964 by subjecting a male lab technician to sexual harassment and failing to address his complaints that a female co-worker was abusing him. The EEOC said the harassment included the female employee touching the male and making inappropriate comments about his appearance. In its suit, the EEOC charged that LensCrafters fostered the hostile climate by disregarding the male technician’s complaints because he was a man.