Scrum itself. Sorry, but when you create a list of ScrumButs and indirectly deride everyone for not being able to take "Full Advantage of Scrum" so that your purists can go out and attack it at full force, yeah, that might be the problem.
The idea that different organizations might actually benefit from not adopting a methodology wholesale isn't that farfetched.
You could argue that's part of the cargo cult, I'd agree to some extent. But it becomes difficult to separate the 2 when you're literally derided for not following it to the religious T.