[Osem]

The point about the wealthy being able to easily absorb the costs and therefore being able to park virtually with impunity is a good one - that's where clamping/towing is more of a deterrent.

As for being confused - well someone has the difficult job of drawing the line somewhere between those diligent/considerate motorists who genuinely get confused through no real fault of their own and those who simply couldn't care less about anyone/anything and operate on the basis that ignorance should be a defence.