You get what you deserve
Imagine using 60 minutes of your time to backbreakingly shovel snow off of a driveway, only for another person’s car to swoop up and take your spot. The level of frustration would be off the charts. You can’t just key the car since that’s a crime, but you can (probably) shovel snow onto their vehicle and get away with it.
The thoughtless, inconsiderate, inhumane people who steal other people’s parking spots are the scum of the Earth. People don’t just clear snow off of parking out of the kindness of their hearts. This car owner should be thankful that the OP didn’t do anything worse to their car.