I love it when people throw tantrums like this because it basically just means they've abandoned any pretense of having a reasonable position.

I remember one time at summer camp I really wanted the top bunk but this other kid just unilaterally decided it was his, didn't rock paper scissors or anything for it, so I'm like, nah, moved his stuff, put mine there instead, two can play at that game. Let's talk.

This kid just went livid, started screaming whining threatening to beat the shit out of me, caused a massive scene, camp counselor came in to have a talk with me, talked about how disappointed they were that I'd do such a thing and how I should give the kid the top bunk, I said, "nope, this kid threatened to assault me and you are trying to reward him for that behavior, what lesson does that teach, I will not 1 the top bunk, if you push the issue I will refuse to share accomodations with the kid altogether because I "won't feel safe" as you are rewarding violent behavior"

I kept the top bunk, nothing came of it.

Parents reward this childish whining when I was a kid it's no surprise they persist with it as adults. This kid didn't get punished for his response, I didn't get punished for just taking his bunk. The admin failed miserably in their jobs. So a generation of those kids are now parents themselves.

I still use this tactic alot, it's very effective.