Even without the high cost of .22's, it seems like a poor idea. There would be limited appeal to my way of thinking. The light .38 loads make recoil a non-issue so that reason does not hold water. I certainly agree that allowing people to shoot .22's should be considered. Maybe that is all they have, or do not reload, or that is what they want to shoot,,,, but they shoot for fun only with the rest of the participants.
I used plink with .22's but it is cheaper to shoot .38's and 9mm nowadays if you reload and cast.
Coffin Filler