XP is not harder than Scrum. Or easier.
The problem/challenge (depending on how you look at it) for any successful adoption of a practice is the willingness of people to change what they are doing now, and stick to it.
If people do not commit, to say, daily stand-ups they wouldn’t do it, even though it’s much easier than doing TDD. Developers do TDD in Typemock because they know it’s better than how they coded before. They were willing to change and they are able to stick to it, also because everyone on the team works like that. “This is the way things are done here”.
Don’t blame the system. Blame human nature. Then get people who are up to the challenge.