The BBC article that this article is a bizarre summary of is far better (the Gizmodo article even links directly to the BBC article). It give a far better overview of the issues; the main crux is they cost most than anticipated through both theft and cost of the machines themselves. The consumer's disliking it is a less point and more naunced essentially "customer's want the technology to work but it isn't" which is also what you've said.
Personally I preferred the self checkouts because I don't want to interact with someone, but th they fail so much (because of the weighing which is to stop me being a supposed thieving scumbag, not to benefit me) and you end up standing around waving at a random stranger to come and fix the machine awkwardly while a massive queue waits impatiently for a machine. I've recently switched back to the manned checkouts for bigger shopping trips.