I don't know enough people in sports to be sure about this, but my guess is that the people who try to fix their mistakes rather than crow about their successes are the ones who improve over time.
If a reporter/interviewer asks you about your failures, and you simply reference your success, does that necessarily mean you do not fix your mistakes?
How do you suggest you 'fix' the mistake of dropping a few balls in a game on the spot? The only answer is, you go out and continue to have big games. This would be akin to an interviewer asking Michael Jordan 'why did you miss 10,000 shots in your game' and he says 'I made XYZ game-winning shots and was NBA Finals MVP.'
If you look at any of the interviews about teammates/opponents of MJ, they all say he was very, very cocky.
Cocky != Refusal to fix mistakes.
Or perhaps, in a better context, an interviewer asking you why some of your stock purchases did not work out favorably, and you stating that you've had a lot of successes despite your failures.
I'm by no means a Michigan fan, but I saw him play a few games last year (on TV) and he was clearly a very, very good football player. Looking at Manningham's stats on Wikipedia http://en.wikipedia.org/wiki/Mario_Manningham he seemed to have a pretty good season last year, when I believe the interview took place.
In certain sports, anyway. In other fields -- customer service, for example -- things are different.
"Oh yeah? Well what about all the times I told people to get some rest and drink lots of fluids?"
Yes, I can see how this would be a good success strategy.
(I do agree that it's important to recognize when you're doing the right thing, especially in a creative field. But when you're playing a game according to strict rules, on a team, the need to avoid failure is probably greater than the need to avoid success. Especially when you consider that the people who make it to these teams probably emphasized pursuing success over avoiding failure when they were younger, because someone in the 50th percentile in a professional sport might have been in the 99th percentile as an amateur. If nothing else, they should dampen their individuality to reflect the higher average performance of their peers).
This happens to musicians a lot.