I generally agree with your sentiments. There is, however, a relatively tricky balance to achieve when attempting to optimize athletic performance.
I think overtraining has become a bit of an epidemic among novice strength trainers, and "less is more" can be a helpful lesson to learn sooner than later... but extreme athletic results often involve extreme training methods. Injury is a line that is always (very) detrimental to cross, but not pushing yourself close to that line can result in you failing to reach full potential.
You could argue that optimizing for some athletic output is not a wise use of resources anyway, especially given the risks (and I might agree with you) But it just may take the most extreme training to produce the most extreme (and optimized) results.
Here's an internal dialogue I just had.
Q: How do we test rationality skills?
A: We haven't come up with a comprehensive test yet.
Q: Maybe we can test some part of rationality?
A: Sure. For example, you could test resistance to akrasia by making two contestants do some simple chores every day. The one who fails first, loses.
Q: That seems like a pointless competition. If I'm feeling competitive, why would I ever skip the chores and lose?
A: Whoa, wait. If competitiveness can cure akrasia, that's pretty cool!
Now we just need to figure out how to make people more competitive in the areas they care about...