Not sure if your implication is that you could do the same thing on any other spot (e.g. a spot for disabled, a load/unload spot, a spot reserved for police car

Not sure if your implication is that you could do the same thing on any other spot (e.g. a spot for disabled, a load/unload spot, a spot reserved for police cars), as long as "people are not waiting for it". In any case, the rule I follow is to move the car where it doesn't block a scarce resource.