I'm not for machines taking over peoples jobs. On the other hand, if the store employs people as cashiers and eliminates self-serve machines, they should then have enough cashiers for convenient, fast check-out. I quit shopping at K-Mart because everytime I went there, it seemed there was one cashier for the entire store. And of course, when you walk in, no one is in line. When you're ready to check out, there's people lined up.
If anything, I rally that they follow Aldi's lead and have super-fast cashiers, and you take care of bagging yourself. No self-serve machine needed. After years of "crap, I picked the slow-as-molasses cashier", and the cashier who chit-chats with customers when there's a long line of people waiting, and the cashier who gets exasperated with me for bringing my own bags, and standing in the express lane while the cashier checks out someone with 50 items... well I didn't like using them, but I have to admit I've gotten pretty good at the self-serve system.