>also notice the moving guys aren't wearing their shoes inside. They are taking them off upon entry, carrying stuff (sometimes really heavy stuff) and putting their shoes back on when removing stuff. That's the part that shocked me.

I've worked granite installation. Some customers demanded we take off our shoes. It's terrifying carrying a piece of stone with someone that weighs several hundred pounds with nothing but socks on. It's also fun trying to get your shoes off while holding said piece of stone. Normally, we'd put it down on the steel toes if we neesed to. Can't do that while you're taking your shoes off. I hated those customers.