How are they this upset?

I mean I work for a council, there's a lot of people who chuck abuse at you for not doing something fast enough. I've been called a retarded jobsworth once for someone not getting a repair done fast enough (not my area, I'm just making sure it goes through on the system and I can see that it's currently with the contractor I don't control how quickly the contractor gets there mate) if you work in a public facing role people are going to be rude. It's not really that bad, they're just frustrated that they feel things aren't being done fast enough. I get it. Would still prefer they stayed polite but I may as well ask for a serious pay rise as the likelihood of both is close to nil lol.

Same for the teachers. Kids can be little shits, it's part of the job to deal with that and getting mad at them is just going to make them do it more in the future. I respect the hell out of that headteacher though, that's what's needed. Some parents are absolutely nuts. If you do anything there you can easily escalate it into an incident. It's a valuable life skill and these people lacking it is doing them a huge disservice.