Wicca is easily disprovable, at least.
As soon as some new convert casts a spell and it fails... and they retry it... perhaps several times... they should see the light if they're not mental.
I think you're confusing "Wicca" with "the beliefs of certain Wiccans". Assuming that all Wiccans hold that every spell ever attempted is indisputably effective is like assuming that Presbyterians believe in transubstantiation, but about five thousand times as simplistic and ignorant.
Wicca is actually a fairly eclectic set of beliefs, the only real thing that all of them hold in common being the Masculine-Feminine duality of the God and Goddess, and even then the exact form that duality takes varies from tradition to tradition or individual to individual. As long as their beliefs incorporate that in some form, and they describe themselves as a "Wiccan", the someone is a Wiccan.
What's more, contrary to the common misconceptions of certain ignorant, self-righteous soapboxers who I won't dignify by naming, most Wiccans do not believe that the religion is in any real way "ancient", but cheerfully acknowledge it's modernity; indeed, within the neopagan community, it is often seen as the archetypal form of revisionist neopaganism, in contrast to the more strictly reconstructionist forms such as Germanic Heathenry. Granted, they claim that it's in the spiritual tradition of ancient paganism, which may be questionable, and some are prone to an overly romantic view of ancient paganism, but that doesn't quite demote it to the levle of "teenage fad", as our pompous friend seems to believe. Many religions have adherents who make questionable, simplistic or ignorant assertions, just as those who are entirely irreligious may. The religion itself can not be written off on such grounds, especially one as eclectic and uncentered as Wicca.
Put simply: A lot of Wiccans are full of crap, but that's because they're human, rather than because they're Wiccan (not to mention that the American ones tend to be more full of it than the European ones, although you can draw your own conclusions from that...), despite what some passive-agressive adolescents may like to think.
Anyway, Scientology. Wicca, for all it's faults, can at least be broadly defined as a "religion" in the everyday sense of the word. Scientology is, instead, a rather disturbing cult. At best, if it
is a religion, it's a bloody awful one.
