1. At a fundamental level, I think this post was telling women that they should be pushovers - or at least implying it. Telling women to support their husbands or boyfriends sexually is good advice for girls who already had strong personal boundaries, but it is questionable advice for a girl with weak boundaries.
2. I am not completely sure that it is a good thing for sex to be 100 % available to a man, even in the context of a relationship. A masculine man is a hunter by nature, and needs a degree of pursuit in his life - including his sexual life. I am extremely hesitant to tell women to actually withhold sex from their man, because this kind of behavior can too easily turn into bribery (which, for a relationship, is way more problematic then sexual boredom); but at the same time, I don't think advising women to be a living sex toy is perfect advice either. If I do find a way of quantifying what I think to be the right balance between those two extremes, I will write a new post about it.
In addition, I have a couple posts that make the good points without making the questionable ones. They are linked below.
You can read the original (though annotated) text of the post here: Never Say No to Sex
1. The Analogy Between Sex and Commitment
2. The Analogy Between Sexual and Emotional Support