Racing bikes are not good for carrying stuff and riding in the rain without fenders sucks. Other than that, there's nothing wrong with commuting on a racing bike. If you live in a place with little rain (like me) and you can avoid having to carry much stuff, it's fine most of the time.

I currently commute on a touring bike. One of these days I plan to get another racing bike and when I do, I will probably commute on it 3 days a week most of the time. I carry my work clothes on Monday morning and Friday evening though so I'll still ride the touring bike those days. Of course, any day it rains will also be a day for the touring bike.