I think in some ways it probably should be handled better. I think the issue of not knowing what you did can be a difficult one.

I expect the GM's have to go into "customer service staff mode", because that's how their replies often read to me and that's tell you something without telling you much at all. It was the challenge service agents struggled with when I worked in complaints, because you are very limited to what you can and can't say. 1) is to combat lawyering and 2) is to not give away information that's inappropriate to give out but that information may have gone behind that decision. And 3) there are legal and policy considerations too.

I think one of the potential struggles is not giving away information that could help you identify the person who raised the ticket against you so it doesn't put their anonymity at risk, especially if it's something that comes to bite them. But at the same time they need to communicate how you violated the rules, but the rules themselves are pretty broad.

Personally, I am not sure what the best solution is for the dilemma, because if you don't know exactly what you did wrong, it's hard to correct that behaviour.