I think the issues people are having with self-checkout kiosks are more about the particular system employed, and the competence of the particular store or business management.
My local Publix stores (five stores I routinely use, depending on what other errands I'm running) all have 4 of them, as well as typically 2-3 human checkers. They also have an attendant whose sole responsibility is to deal with the occasional...and rare...self-check glitch.
I've been using the self-checks there for more than a decade, because I can blow through and get out the door while the human checkers are dealing with coupons, folks who don't know their PINs, folks trying to buy booze with food stamps or pay with paper checks and no ID, etc.
I've also used self-check in Walmart stores, both here and in Az., and Kroger stores here and their affiliates in Az., and have had zero real complaints.
EDIT: As an aside, I've rarely had the pleasure of dealing with any business that's as consistently competent as Publix. They do, of course, have the odd employee who's apparently not focussed and fuds something up, but in general, their stores here have been doing a fine job since I moved to this part of town in 1999.