I like to take the view that people generally at boat ramps aren't acting maliciously, and if they are doing something silly like blocking the ramp its because they don't know any better or were unaware of what they were doing. After all, I think most boaties especially on weekends aren't regulars. If someone is blocking the ramp, taking a lot of time rigging or loading/unloading, I find if you offer them a friendly smile and offer a hand they usually get out of the way pretty quick. Getting agro with something will usually get a negative response, which is quite natural, not really what you want and doesn't usually speed things up anyway.
I know when I first started I was a bit slow loading/unloading and getting the motor started. It would have been nice if someone offered to help rather than give death stares. After all, boating/fishing is for relaxation rather than a high stress, competitive extension of our working lives.