Believe it or not, it's not just with non-FFs... my parents travel fairly often (internationally at least 2-3 times per year, domestically about 6-8 times) and even they get confused by the EZ-Checkin, at least for international flights. They don't check bags often so on those occasions when they do (e.g. a couple of days ago on an outbound int'l flight) they don't remember that they can still use OLCI or EZ-Checkin and a human will still tag their bags - they seem to think they need a human the entire way through. For whatever reason, they also don't realize that both OLCI and EZ-Checkin can handle passports for int'l flights; I had to point this out to them a couple of days ago.

It's very surprising to me how someone who should know all of these things backwards and forwards can still get confused. My mother will hit 1K for the first time this year, and even she was asking the agent behind the kiosks a bunch of questions. Some people just don't really pay attention. (And she's not intimidated by technology, so in her case I think it can just be summed up by not paying attention to things... in my father's case, it's just paranoia that the machine will screw something up, although I have no idea why he has more faith in humans given that they have a tendency to screw things up, too. )