dibs958 wrote: Are some campers simply taking up too much room
No I don't think so, but some campsite like to cram you in like battery hens, C&CC are good at this with there maximum pitch sizes. Go to Pillaton Pools and you need a compass to hike to your nearest neighbor, then take a look at Shell Island and you can pitch where you ant as long as you stay 20M away from your nearest existing neighbor.

This us crammed in like sardines at Lane Side Caravan Park in Hope (Peak District). I won't be returning there ever, just glad I didn't take the Vermont or we wouldn't have got it on.

Pillaton Pools, taken from my tent looking across at Robs tent on the next pitch

Shell Island, we were set up close because we were all together and it was our choice, but then notice no one is near us and we have plenty of room
Its always worth checking out reviews for a site and trying to look down at the site from Google earth to get an idea and steer away from the sites that say you have a big tent and need to go on a super sized pitch.
Just my opinion, I like to meet and chat to other campers, but I don't like to share the same tent pegs
