The clutch is there to help you change gears it doesn't protect anything. If you leave it in gear when parked the clutch is engaged so the force of any blow will transmit through the drivetrain.
People in the US who don't use the parking brake don't know any better! I caught my wife doing it, with both a manual and automatic tranmission, I asked her to use the parking brake all the time.
Also a good rule of thumb, with an automatic transmission, is to set the parking brake first before putting the transmission into "Park".
retroom