Who are you to decide what is a constructive use of time for others?
Actually, wing shooting is a highly challenging sport and takes a lot of practice to attain competency. Somehow, as a wing shooter myself, I have managed to learn to also play a musical instrument and found the time to earn an advance degree. So participating has not inhibited my ability to do these other things you feel are constructive.
Wild rabbit tastes quite a bit better than farmed, as do grouse, wild turkey and pheasant. Also, hunting is an environmentally sound practice, unlike most industrial meat farming operations.
Further, my children who also participate, have a greater understanding of where their food comes from, and that meat doesn't just arrive on the supermarket shelves without some sacrifice. This is the most important part IMO.
As for this derail, do you have any evidence that shotgunners/wingshooters have participated in or that the sport has caused mass shootings like we're supposed to be talking about here?