Let me observe that both men and women don't just want to find someone of the opposite sex, they would like to be with someone who is as good as possible. When you are with a person who is as good as is possible for you to land, that person will be someone you have difficulty getting to be interested in you like you're interested in them.
So, for instance, a man who dares say something moderately insulting to a woman early on establishes that he thinks that he could do better. If he does not offend her too badly and turns around and gives her some hope, that gives her the message that he's someone she has a chance at but has to work for. If she believes that message, she'll think of him as a good potential catch.
Going the other way, a woman who doesn't feel compelled to return a man's calls promptly, puts off sex, and who insists from the start on time for herself is demonstrating that she believes she is a reach for him. If he believes her, then he is more likely to work to establish the relationship, including making the commitment to take care of her and help raise their children. (Which is what marriage is.) No man likes those games, but most of us respond to them.
These parallel pieces of advice are both effective and offensive. You'll find the advice for men as part of the standard repertoire in virtually any guide for pickup artists. It is standard because experience shows that it helps get women in bed. Conversely the advice for women is straight from http://www.amazon.com/Rules-TM-Time-Tested-Secrets-Capturing.... That is sort of a female counterpart to the pickup artists guide and is about how to land a man who will commit. The polarization of the reviews is evidence of both offensiveness and the gratitude of women who found the advice effective. (Read the reviews and you can verify the reasons for the votes.)
So there is a concrete example for you. Landing someone of the opposite sex and getting them to do what we want them to do is of interest to the vast majority of us. (Yes, some people are gay or asexual, but the vast majority are straight heterosexuals.) Yet advice that is effective for that is quite offensive.
And, of course, when we're offended by advice about the sexes, we usually call it sexist.
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