The flip side to this is that older teams, more aware of their limits, may play a more conservative game, funding more carefully from operations, and the like. This means also less of a need for VC funding, and it means less of an opportunity for VC's to leverage successive rounds to dilute founder's shares.
I couldn't find the article, but I read somewhere that the rate of success for older entrepreneurs is higher than for younger ones, because of their accumulated experience and wisdom. There's definitely a flip side.
In other words, lower risk, lower rewards.