Well, I can only base my judgement on what I've seen quoted here: I'm not giving the NYT my name for yet another mailing list, quite honestly.
That said, I think Pielorhino makes some very valid points. For one thing, the author paints with a broad brush, but ignores a large body of material so that he can make his point. Are all of his points, unflattering or no, incorrect? I don't think so, but they smack of 'well, the nerds won.' The implication being that anything that is fantasy is something we'll all have to learn to live with.
I might posit that Star Wars hardly can be classified as something that only appeals to a very small cross-section of fantasy geeks. Quite the contrary, in fact. Does Andre Norton? Probably, but let's be honest: we're talking about escapist fiction, for the most part, not Henry Miller. In many cases, sex is either not important or not appropriate to the story.
Colonel, I think you'd agree that in Tolkein's case, (never mind the issue of his style or the story itself) much of the mythos from which he drew rarely went into lavish detail about such relationships. In a poem like Beowulf, we're not lavished with a lengthy sex scene...we're given a line or two, at best. The same would apply for tales from the Bible (say, Samson and Delilah) or any number of historical mythological texts (of which the Greek myths spring to mind, and Zeus conquests in particular).
That said, if one is going to point out, as the author does, that mainstream fantasy, particuarly Hollywood's interpetations therein, avoids this material, that he's being overly general. I certainly think he probably doesn't group Anne Rice in with the fantasy genre, for example. I tend to think that intentional myopia is more the cause than anything else. He sees what he wants to see, essentially.
I would also disagree with you concerning authors like, say McCafferey, who were popular enough in middle-school over 20 years ago for me, and were well read by more than just the geeks. The author also seems to ignore the huge female readership that fantasy has, in his quick desire to describe a large group. You mention the sales of Star Trek books, and rightfully so. I would guess that the author would ignore them, because he doesn't classify them as fantasy, and that he Star Trek (like Star Wars) has become so mainstream in it's day, that no one views it the way the once did.
The author thinks that's because they've lost some sort of fight, I guess. I don't think he's really being derogative...I just wish he'd make an effort to try and be more precise. It's like reading the review of the Scooby-Doo film that starts out by saying "I've never ever understood the appeal of Scooby-Doo for 30 years.". Regardless of whether or not he liked the film (and I know I will, if my kids make me see it), it shows the angle he's thinking along. Perhaps this author needed such a statement himself.