Do you not ever stop in an emergency? That's when I appreciate an inch of space between me and the TT.
...many of the poorly fitted (too small) bikes I have seen are not race bikes.
One of the prevailing thoughts about purchasing a bike is to pick the smaller, if you're between sizes. Ads show off race bikes. Conventional wisdom is that lighter is better in bikes. I think marketing has more than a bit of influence on how bikes are set up.
And that's without considering the fact that one usually doesn't see enough with one's own eyes to support much in the way of generalizations.