I prefer self-checkout because cashiers don't know shit about bagging groceries in a reasonable manner. I don't like dealing with people and I like my groceries bagged to my specifications. Self-checkout is a godsend.
That said...
I have made mistakes. I've accidently stolen from WalMart. I've been an employee of WalMart; I am not crying over this. WalMart is a shit employer and they have a ton of self-check so they can continue to refuse full time jobs to cashiers so they don't have to pay benefits. Fuck them.