I believe they were the ones to stop selling ammo or something after one of the shootings.
This is not a surprise and won't help their sales. The people that they're catering to wouldn't have bought a scary, evil, black gun to begin with!
IMO: Dick's is just a clothing store that sells the overpriced Nike and Underarmour type crap. The sporting goods around the perimeter of the store are mostly to give an authentic feel to the clothes. People want to feel like they really are serious about their outdoor/athletic pursuits by spending a bunch of money on stylish clothes. The sporting goods just set the mood.
If they sell the occasional pair of ice skates, bowling ball, or deer rifle it's all good; but, not really important to their profitability.