Could be. Here’s another take:
I really prefer to find a manager and tell them why. I’ll spend time trying to hunt one down on the floor to do that. I see it as a public service, me investing my time in driving a business towards understanding that their shortsighted choices are costing them money and customers.
It’s very inefficient for me to do this. I then need to go to another store and re-load a different cart with the same goods. Or I need to come back to this one at an off-peak time and again repeat my effort.
Be the change you want to see. I want to see businesses that have enough cashiers on duty so wait times are minimal. So I do the things that I believe will encourage that behavior. Silently grousing in line while accepting the unacceptable because its “easy” is the dumb, shortsighted, and ultimately selfish anti-social thing to do in my POV.
YMMV.