Because this person doesn't ever actual disprove any of Martin's claims or show that the science and research she used to formulate them is flawed. He (I'm assuming he's a he based on how outraged he is about female sexuality) just makes largely meaningless attacks. For example, at one point he complains that the science she uses ranges from biology, to primatology to anthropology - as if that were a negative instead of exactly the way that real scientific theories get formed, by drawing on a wide variety of subject matter areas that all point in the same direction.

Martin references a wide body of newer research that indicates that women get bored with monogamy earlier than men do. Study after study from around the globe has found this to be true. Women in committed relationships get tired of the same old same old sex and it tends to shut down their libido. He characterizes this as her "talking down to women" when it's really just reporting what current research indicates and pulling back the veil on a whole bunch of myths about female sexuality. Women don't lose interest in sex in monogamous relationships because women are less sexual, they lose interest because they are bored and it shuts their sex drive down. That's a really, really important distinction in my mind. But he doesn’t like to hear that for some reason.

He goes on and on with similar diatribes that don't actually disprove her points (many of which are quite mainstream at this juncture). He just lobs credibility bombs and rants. It's a very lazy critique made by somebody who clearly has a chip on his shoulder.