I think it is a racing thing. The shorter geometry should allow less flex, and probably when it comes down to it, weight (Short vs long stays).

It is aggravating if your trying to use a sporty road bike for more practical purposes. I tried putting 27 1 1/4 Pasela TG's on my Motobecane, and just because of the difference between a 27 1/4 specialized tire and a 27 1 1/4 Pasela to go from perfect to rubbing the back of the FD clamp. Forget about a traditional fender for the same reason.

It's my summer commuter for that reasoning alone. Now has 27x1 Pasela TG's. The Cannondale gets the most commuting duty, due to it's excess of racks, longer geometry, fenders, and 700x32 tires (down from the 700x35 that it came with).