These things are real unpopular, both with workers whose jobs are threatened and with consumers who are now either honorary employees or de facto shoplifters.
I work computers for a living; I work computers in my free time. Sometimes I enjoy having a little break from working a computer to look a human being in the eye, say hello and thank you. In fact I often enjoy customer service transactions as the only friendly human interactions I might have all week.
I've witnessed a stream of articles saying bad things about self-checkouts and convincing consumers to avoid self-checkout. Since I'm cynical, I believe there's money and lobbying behind those articles, not a true problem or concern. Nevertheless, I'm sorry that there are fewer humans to greet me and help me in the store these days. I miss you guys.