As an American who's never so much as been to the British Isles, I'm obviously ignorant of the inner-workings and politickings of the festival, however, having helped run a (very, very) small one in the States before and being close to people involved in organizing larger festivals, I feel like it's worth considering that this was just overlooked until someone brought it up. With a festival, especially a large one, it's not hard for things to fall through the cracks, especially if it's been one particular way for years.

This is not to say that Sidmouth didn't have ulterior motives in canceling this "LNE," but it's not necessarily nefarious.