Wicca deserves no more respect than Scientology, or any other religion. The fact that wiccans are relatively harmless woo-woos who dance around naked makes them less immediately harmful than other religions, but they are as delusional as all of the others, and if they don't perpetuate themselves by door-stepping, they certainly brain-wash their children like all of the other believers.
I have a friend that practices. You wouldn't actually know she did until she told you. As far as I am concerned, as long as your beliefs don't encourage people to commit violence or discriminate against others, what is the harm in letting them practice?