Baud said:
I got the impression (maybe I read part of the book wrong) that what Hutton was saying was that Gardner's Wicca was based among other things on Murray's thesis of witchcraft as a religion, on the theories of folklorists such as Frazer, and on the Goddess theory of a single mother goddess worshispped uniformly throughout Europe in prehistoric times. He argued that, while these three theories were accepted in scholarly circles at the time Gardner created Wicca, further research has shown that no evidence could confirm them, which doesn't mean they are necessarily false, but rather unproven.
I think you are interpreting Hutton's work correctly. That's how I understand it, anyways, and it seems to be how others like Isaac Bonewits describe it in his book "Witchcraft: A Concise Guide."
While theories like these might not prove as historically valid as Gardner would have liked, the theories themselves can be very useful as the basis for a spiritual practice. An idea doesn't need to be old to be good.
It puzzles me a bit how often people seem to get hung up on the "universal goddess" part of the goddess-worship idea. I seriously doubt there was a widespread religion of a single universal goddess, but there isn't much doubt at all that there were goddesses worshipped by many many people in the past. Just because the universal goddess claim didn't hold up to scrutiny it doesn't mean that considering any form of the Divine to be female should be considered bunk.
There does appear to be some evidence going quite far back, however, for the idea of a single "great goddess" that is considered to have a multitude of different faces and names which are enumerated from a variety of cultures. In Wicca, we have that idea reinforced in The Charge of the Goddess: "...the Great Mother, Who was of old called among men Artemis, Astarte, Diana, Melusine, Aphrodite, Cerridwen, Dana, Arianrhod, Isis, Bride, and by many other Names." The idea comes across quite clearly in Lucius Apuleius' "Golden Ass" towards the end. In the translation by Robert Graves, it's in chapter 17, "The Goddess Isis Intervenes." Apuleius lived around 120 CE to 170 CE. Copies of the original Latin and another English translation (from 1566) are online at
http://www.jnanam.net/golden-ass/#ed
While the specific religion of Wicca does appear to have originated with Gardner, he quite definitely built it up using older bits of information from a wide variety of sources. The mistake is always in assuming that because bits and pieces within Wicca are ancient, that somehow this proves the whole is also ancient. Anyone can create a brand new religion today and put something in it from a truly ancient source; this doesn't make this new religion automatically as old as the oldest component bit.
And just to reiterate... I'm a Wiccan myself, and quite happy practicing Wicca regardless of the age of the religion as a whole, and regardless how ancient any of the ideas might prove to be. If it works for me, that's what is important. History helps us to learn where things came from, and helps us to spot trends in things, but it isn't the sole criteria for whether an idea is useful or not.