.....Instead I'd be interested to know how many legitimate cavers they keep out because it's more faff to organize a trip. That's the big issue.
Indeed, this is a major point. Although the caving community 'bubble' is the significant group, and I expect access for the vast majority within it is easy, there will be other cavers on the outside who do not know the system nor have the local connections which others find so easy.
There are parallels to the permit system in the Dales which I am more familiar with. Similarly it was claimed to be a simple system for all legitimate cavers, and it was, for those in the know and within the caving community bubble. Just as with the keys on Mendip, local cavers, regulars if you like, could get a permit with ease.
As I got involved with access in the north, and coming from outside the permit community bubble myself, I realised many legitimate groups were either put off by it or ignored it. These could be groups of individual cavers or clubs from outside the area and likely some from outside of BCA membership too.
Just one of many examples of this was a group of National Park rangers who had stopped caving in the Dales as legitimate access through the permit system was too much 'faff'. This came to light, by chance, at a National Park meeting which I attended to promote caving. The permit system had been a barrier to this group for many years and was an eye-opener to the plight of other legitimate cavers.
The point is that within the 'caving community bubble' you don't really get to know who you are putting off caving in your area. No one really does. Why do anything about it when the community is happy with the system? That very much depends on the attitude of those in charge and whether they want to encourage caving, remove barriers and open up to a much wider outdoor demographic.
That is my experience anyway.