Defilers of public washrooms. I've been doing a lot of travel recently. I have an ostomy so I haven't had to "sit down" in a bathroom for several years but for decades before that I did have to do that frequently due to a chronic illness. Travel then was a sheer nightmare of filthy bathroom after filthy bathroom. I still feel anger on behalf of others like me or people traveling with small children etc.
The people that basically destroy toilet stalls are the worst. I walked into a stall yesterday and it was soaked from one end to the other including all over the seat, etc. There was so much on the floor it was obvious this was intentional.
Why? What kind of monster did this?
That same trip I went into a bathroom and every stall was inexplicably filled with guys just hanging out. There was a bunch of them all getting changed or something. I waited 15 minutes before giving up. I had nothing better to do since every flight is basically delayed now. I know there's really nowhere else to get changed in an airport but maybe, you know, go two at a time. Other people exist.
Anyway, people who are just cruel in an anonymous, nihlist way. That's it.
People who are in their car, driving.
This is only whole they are driving, and it applies to almost every person.
People really lose it when they are driving a vehicle. Either they are a psycho behind the wheel or too non committal and mess up traffic.
I am included in this data set, I'm both groups, depending on the day.
People who are unable to feel empathy for others outside of their "in-group". Racism, oppression, genocide, all of it stems from that same basic disorder. Unfortunately this is an all too common trait in humans.
People who lean into being douche bags/trashy because pissing off/offending other people is the only thing that makes them feel good about themselves.
They often wear shirts that say stuff like "FBI, Female Body Inspector" or "You stomp my flag, I stomp you." With a picture of the American flag on it.
They often drive lifted trucks with fat offroad tires and push bars with a punisher skull or some kind of gun-related/blue lives matter decal stuck on the back.
We're not in a good place as a species when the first answer that comes to mind is "where do we even start with this?"
After some thought, my answer would be people who sacrifice another's long term prosperity for short term enjoyment. That's what most of my answers boil down to.