> but if so many people get it wrong there seem to be a fundamental problem with scrum
It's the same problem with all methodologies - if the management is in charge of the process and it doesn't like some aspect of the process it will ignore that aspect.
If Scrum is X, but everyone saying "Scrum" is referring to Y, is Scrum X or Y?
The answer is it doesn't matter. The problem here is that people are doing Y not X, and discussing semantics is only useful as an appeal to authority (which to be fair can be pretty darn useful sometimes).
Scrum/Agile are useful tools to get buy in and a bit of restructuring done, but I feel as soon as you start doing real work you will just have to figure out what flavor works for your team, and what modifications need to be made to the process to make that happen.
I don't doubt that's true, but it's not how things are supposed to work in scrum: https://www.scrum.org/resources/commitment-vs-forecast