I know I'm a little bit older than some other posters and that things were done differently in my collegiate days so my view on this is colored by that; but I simply cannot relate to treating any race as a workout. When I, or any athlete I coach, laced up the spikes or flats, puts on the singlet, and toes the line, I expect a full race effort. I fear that half hearted efforts in race setting beget half hearted efforts in race setting. Racing is a mindset as much as it is a physical act. Running hard hurts. We all look to cut deals with ourselves during the pain. Turning a race into "a good workout" becomes an easier deal to cut when you've treated races as workouts in the past.
Again, I understand that this is my early-90s college bias impacting my view some, and I get that most view racing every week to be detrimental to improvement; but I would prefer an athlete work it out either his coach that he doesn't race at a particular meet than have him race at less than a max effort.