You can't say for sure one way or the other which is "preferred" based on the data. It may SEEM to be preferred but that may or may not actually be true.
Going by what you see at campgrounds, you're going to largely see the "sheep" that did what the RV salesperson said because they didn't know any better and could not be bothered to do their own homework. They tend to go with the cheapest option, or blindly buy whatever the salesperson recommends. Show up at a campground with something different and you'll get all kinds of attention, "Oooh, where did you get THAT!"
It doesn't take a genius to figure out why a gooseneck MIGHT be preferred: A 5lb ball that you pop out and flip over, vs. a 250lb structure that is significantly more effort to install and remove no matter how you do it.