While not a coach (yet), I was fortunate enough to have a very reasonable and rational coach. Most dual meets would used as tempo workouts for the top guys, while some of the runners that were not able to run in invitationals would use them as races. Usually, we would race the 2 mile and mile (depending on the length in between races) as tempos with maybe partial workouts throughout them. For instance, 3200m with 200m on, 200m off, at 35 for ons and 40 for offs. Usually this was followed by an extended warm down of 4-5 miles. Our theory was that we had put so much effort and concentration into our training with our goals aimed at the end of the season, that dual meets were just tune-ups. Don't expect other coaches and parents on opposing teams to be totally thrilled about this. We ran a dual meet against one team where the opposing parents booed us as we finished. In terms of explaining this to your own runners, as long as you have a good relationship with them and they trust your training methods, then they should understand.
Also, for those saying that a race is a race that's way too idealized. I was what most would consider a good racer--albeit it wasn't the strongest section-- and when I raced it required a large effort, both physically and mentally. You can't expect anyone to exert that much effort 2-3 times a week.