The show makes a joke out of male chauvinism and male ego. When Bob says Donna never would've been president of a company because she's "a gal" in Season 7, it's a joke for the audience. The viewers are So Much Beyond that sort of thing. "Of course women can do want they want!" they think. Eric's insecurities in "Battle of the Sexists" are also jokes, such as when he imagines himself in a dress with inflating breasts.
But it's the subtler, underlying values that really do damage. Like when Donna stays home from college to be with Eric, about the stupidest thing ever, and yet later Eric abandons her to seek his future in Africa. To be a girl or wear a dress is the ultimate denigration for the teenage boys. When Kelso falls off the water tower in Season 1, the boys in the hospital room automatically watch the nurse's behind, because that's what boys too.
But the worst thing is the rape culture that the show supports. More about that next time.