People are idiots. Not all people, of course, but some people are most definitely idiots.
I'm attempting to get a job at Gamestop, as well. (It looks like I have a good chance too, as some of them are just now hiring for the holidays.) This series has made me a little apprehensive about what I may experience there, but I believe it has also helped me to understand the tasks I would be set and the perspectives of the company, the manager, the employee, and even the customers.
On the topic of digital distribution, I greatly prefer the physical copy, as I'm a collector (I realized that a while ago. It's why I don't rent or borrow games as much, too.), and want to have that substantial proof of that box sitting on my shelf. I have nothing against digital distribution, it's just not my preferred medium.
Comparing games to books is impractical, though. Reading an eBook is fundamentally different from a hard copy - everything is different to the senses. Playing a game is the opposite - the actual act of playing a game is identical.
I believe that physical copies are far from doomed, and that they will remain for at least a long time, if not permanently.
On a slightly unrelated topic, I actually don't get most of my games from a retailer like Gamestop. I order them from Amazon. You can do it without even leaving the house, and oftentimes it's even cheaper. (It's possible to get no tax as a member and there are often sales and discounts - if not as big as Steam's)