@Ragman,
That used to be called tare back in my lab days, Rags.
Me, I like conversations with the clerks and, like Chai, maybe other customers.
It's part of my social life, heh.
On the other hand, when I have tried the self serve machines, I'm just not fast enough at it, and I don't like lines of people waiting for me to do something. Part of this is my vision/clumsiness thing, sort of the opposite of Soz' situation. I probably haven't had produce in my cart when I did use them - having to figure out how to check those would probably ramp up my anxiety quotient.
I've always been a little slow to understand machines, even when I ran labs. Luckily, once I caught on, usually quickly enough in any case, I was quite the swifty, but there was always a short period of machine tharn for me.
edit - (just saw Set's post)