I used to be that guy, all self-righteous that someone could take a handicapped spot without visible disability, until someone called me on it. So embarrassing, but completely deserved and a valuable lesson

I don’t know if we can generalize from my personal experience but at the time, I leaned more conservative. My outrage was that someone broke the rules, was getting away with something unless someone called them on it. Of course now I understand the result is more important than the rules, that people can have all sorts of physical limitations, visible and invisible, that most people do the right thing most of the time, and “who am I to judge?”