Is their a shortage? Yes.
But, your professor is right in a way. The general managers/district managers etc. aren't too fussed because it means they can get away with having one pharmacist fill 500 scripts because there is no one else to help. Normally, they would have to pay 3 pharmacists to do that. Cha-ching. It makes their wage numbers look stupendous!
As long as they can find one body to be there then they don't care. I have worked in a region where there was HUGE shortage and whenever the idea of closing a store was brought up by the store manager it was quickly shot down. So we chugged away with short staffing and fly by night pharmacists until I got too scared and burnt out.
The retail chains are having no problems staffing new stores because they offer these huge sign on bonuses that always get a few people to jump ship, but that leaves the place they left in dite straits. Its just a vicious circle. I don't understand how if "retail chains close stores everyday" would back up his point? That seems to show there is a shortage or they wouldnt have to close them. I doubt its because they aren't making money.
I would take anything a professor says that doesn't work in the "real world" about working with a grain of salt. Sure, listen to his aminoglycoside pharmaokinetic analysis, but I'd pass on his opinions of the opportunities for a clinical retail pharmacy.