The fact that we make public spaces sterile and miserable for families and children is a choice based on our country's core value of hating poor people.
We were parked there, on the public street not blocking a driveway or fire hydrant, for two hours and discovered the note as we were leaving. Some of you need to relax. And remember that you don't own the street in front of your house.
In this case the Subaru driver was still able to park directly in front of their house (as mentioned in the note). They also could have parked in their private driveway leading up to their private garage.
Counterpoint: Trader Joe's parking lots are good because they are right sized. The ideal parking lot is always full, always has people coming and going, and induces no further demand.