Yep, at Fry's I used to let the exit checker wipe the pink pen on my receipt if no one else was in line, or maybe one person in front of me. It let them feel like they were doing their job, and it didn't cost me much time.
But if a few people were in line, I would just nod and smile and walk on by.
I never had an exit checker question this (they were trained not to!) but I did get a few dirty looks from other customers.
Sorry friends, it's not my fault if you don't know the rules. ;-)
Even Costco couldn't detain me if I didn't let them inspect my cart. But as you noted, they could refuse to let me shop there again.
Of course it would be my loss. Even if nothing else, the membership is worth it for the olive oil!
Did you happen to score any of the 2020 organic Val di Mazara? I've been a huge fan of their Toscana year after year, but the Val di Mazara is something else. Such a delightful peppery oil. I hope they get it again in the next harvest.