I would agree with that to a certain extent. Having a tradition with a lot of history behind it is something that feels more emotionally compelling to people. That is why for example when the Christmas tree was introduced to england and the US in the Victorian time it very quickly became thought of as an old tradition(it was just not theirs) because time adds weight to tradition.
As for wicka and such, I really don't understand why people find it emotionally compelling, it does not seem to have a strong individual claiming divine revelation or a long history.
Gardner compensated for the lack of a tradition with a fictional one. While factually untrue the incorporation of older shamanistic traditions and of a few speculations from poor debunked Maggie Murray seems to give it sufficient patina to be compelling.
Do we have any Jedi here by the way?