I'm still not sure how I feel about taking advice from people who have failed a lot. All other things being equal, I'd rather take advice from people who have always been successful.

I think maybe they can be distinguished by whether they bang their head against a wall until reality finally cracks their thick skull or they attack hard problems until their learning curve catches up. It's hard to tell the difference, but intuitively I feel like it is there to be found.

For what it's worth, the people who make me think they fall into the former camp seem to converge on Scrum as they start to react to their string of failures. I don't have any data on that.