I think it's more than just a fandom thing.
Technically, Jedi is the 4th largest religion in the UK.
I think it's part of a move to attack the established faiths too, we soo much about Islam, and so many attacks against Christianity, that these people are proclaiming their 'belief' yet it's something that hasn't caused wars and death (yet).
It's the same with Wicca, paganism and satanism... they are i believe officially recognised beliefs in the UK, yet have less foloowers than the 'Jedi's'.