I guess it's not proven, though it seems intuitively obvious (which, I admit, is often the sign of pitfalls) ;). I think what hit me during that talk wasn't glorification of competition per se, it was promoting ruthless competition. In the end, team sports and tech challenges are healthy as long as everyone remembers it's just a game and doesn't treat it too seriously. It works in business too, but there people often forget - sometimes because of greed, and sometimes because money is like hit points - losing them hurts; lose enough and you die.

Also interesting note: from my experience, most tech companies aren't really competitive. The market is big enough that most successful companies either compete superficially or sometimes outright cooperate, even when working in the same market.