You're talking complete Yorkshire sense as usual. I say that, because I don't like Green field site Festivals either.
I would like to think a village, town or city benefits in kind by the use of its amenities by interlopers and that the interlopers see a side of the town, which one normally wouldn't. In this case, although you go for the Beverley Festival, surely you must also visit the Minster and its other churches, or eating houses, or purchasing food from the shops. It puts money into a local economy, not to mention the benefit to publicans who seem to be going through a well-documented hard time these days.
Apparently these boozers in Beverley have developed into a hot bed of music sessions, mostly as a by-product of the festival(s), so, the label "folk music" may not necessarily be as bad as it first sounded to Landlords, especially as it appears as it might be another useful source of income for them.
Sounds like everyone is a winner – I know GedPipes loves it there.