Here are 2 thoughts about National Convention locations. If you pick a spot that is too enchanting you get into several problems. 1st, may be a lot of other people want to visit the same area which leads to competition for, and higher prices on the accommodations. 2nd, if there are that many boffo attractions, no one is going to be at the host hotel to buy parts and interact when civilians come by to look at the cars.
In regards to the 2nd thesis, I am specifically thinking of the National in Portland OR where everyone disappeared on tours after 8 AM and didn't show back at the hotel until 6 PM.