Well, that's the kind of story you'd expect when a gynecologist decides to try his hand and anthropology. Lot of logical gaps in there.
It ignores, for instance, the occurance of hundreds of other "henges" that don't resemble... er, what Stonehenge supposedly resembles... in the least. Since they were from the same archeological horizon and are clearly related phenomena, the lack of this latest theory in explaining them is damningly faulty.
Also, the rather blanket use of "ancient cultures" and their reverence of "mother goddesses" is also ludicrous. That is true of the "Old European" cultures of the Balkans and southern Europe, but there's no indication that it has anything whatsoever to do with the cultures of northern Europe or the British Isles, and if those cultures were specifically Indo-European (a hotly debated if, at that) then they were very patriarchal in mythology revering a sky-father figure, not an earth-mother figure, unlike the "mother goddess" worshipping cultures of the south.