1. Equality under the law/Equal rights as humans -- the law should treat men and women equally. "It is wrong to punish men more severely for crimes than women."
2. "Societal" equality -- the attitudes and viewpoints of mainstream society should consider men and women to be equal. "It is wrong to believe that women should have children."
3. Statistical equality -- men and women must be statistically identical for a politically useful class of statistics (e.g., intelligence). "Anyone who speculates that women are not as smart as/have different variance/etc is a sexist."
4. Equality of outcome -- men and women should achieve the same outcomes, for a politically useful class of endeavors. "Professors in every field should be 50% male, 50% female."
#1 and #2 are moral questions, #3 is a scientific one. #4 is a consequence of #1,#2 and #3. The moral statements are hardly rubbish, they are perfectly legitimate moral claims (I even agree with #1). The bullshit is trying to claim that 1 == 2 == 3 == 4.
http://en.wikipedia.org/wiki/Modus_tollens
That's not the point. In politics, if you can trick people into believe rubbish X causes trash Y which leads to bullshit Z and make money off it, then that's what you do. Generally, it's best to have a semi-reasonable argument. In the case above, the flaw is in the statement "Men and women are equal", which is obviously not the case. (Nothing is equal to anything, except in pure mathematics.)
Really, saying "men and women are equal" is a moral statement, with built-in failure, like the commands in the sermon on the mount. This leads to built-in transgression. Which leads to guilt. Which leads to submission. And so on.