Going out on a limb here, LOL, but to me it seems to be either a lack of experience or a lack of plain old common courtesy. Don't have a lot of the "big" boats around here, but I've seen the behaviour which you describe displayed by clowns in fishing boats, jetskis, etc.... One of the last gatherings we attended though, there were boats of all shapes & sizes. Some of the peeps hanging out by us on the beach, had "big" boats & were cool as hell. By which I mean they were aware of the people around them & didn't come in plowing a bigass wake or keep cruising back & forth wrecking all the smaller boats that were tied along the beach there.
Then there were the ones that everybody hates & likes to bash. Not really the size of the boat I guess, but the size of the asshole behind the wheel.