Highbeam while parked?

While driving here, if a car is parked on the opposite side of the road - facing you - why do they always have their freakin high beam on to blind you completely? In my country the custom is to have position lights or at max the low beams on if you're parked on the side. What is this culture here to park in high beam and blind the oncoming person for no reason? Is there a genuine reason, or just part of the "bad driving" culture?