I won't judge based on the post, could be an idiot, or not. I can say that any park that allows 15' tall trailers in as guests should reasonable expect to need the trees cut back to accomodate them. That site looks like a pull through so he was going to at least contact the branches if he pulled through.
One of my pet peeves is parks that refuse to trim the trees back to allow free access to the trailers they book as their livelyhood. I don't have anything against trees. I DO have something against trees dragging on my trailer as I move through a campground.