My mom worked there over 30 years, the same store I did. She wasn't a manager, she didn't want to be, but she worked as the office manager. They eventually got rid of her position. Kmart bought Sears, but Sears took over. It was rode hard to the bottom, as if that was the intention from the beginning. Kmart was mismanaged to begin with, but there was a certain lust for destruction with Sears.
Anyway, it is and was hard to work there. You stayed for the people, and because you needed the job. After so long you can do the job in your sleep--and often do, especially around the holidays--and not a lot of those skills translate to a new company. At least he made it to management, but it's retail management. It's cutthroat and exhausting, I'm glad I didn't go into it or else I'd be in his position right about now.
Retail is hard ... you're right, not a great place for advancement or decent working conditions It's especially bad now with the internet. It's difficult for brick and mortar to compete.
It's gotta be really hard to work at a place like that for so long, work your way up from cashier to manager and then get dumped because of poor management of the company. No matter where most folks work they generally become close, with some like family, but others not so much. I feel for the guy, but life goes on. He'll pick himself up and move onto bigger and better things, I'm sure. It's just a hard transition.