I think it is because they like to keep things fairly simple. Kind of wild camping with toilets and showers. Plus a lot of the people who use it are one nighters, climbers/hillwalkers/student clubs etc. But we are usually the rowdy ones!
The quechua does survive the wind but it does tend to fold especially if the caps are opened out. We were impressed by the vango Kela air that some one had at Gairloch as it didn't budge in the wind. It is pricey but we have just invested in one
http://www.boatofgartenholidaypark.com/ Try this one. It is years and years since we were there but it was a good central place to be, nice and close to Landmark!
Saturday 24th seems the favoured date for August we will be there probably heading up on the Friday night. We will let the owner know so we can have a reserved spot!
Dunslair we will save you one some where on the site!