You have to be a bit more sympathetic to the petrol stations. There must have been bad experiences for the helmets-off policy to have been adopted in so many places. It's not universal, thank heavens. My local is a Morrisons place and, even though it asks bikers to de-hat, they don't enforce it. In my case, when I first went in I apologised for keeping my helmet on with the excuse that it's a bugger taking it off when you wear specs, which they seemed to think was a reasonable approach. If you don't wear specs, what's the issue?