Part of the issue is this seems to be done mostly by people who have very poor ability with technology. It's one thing when someone takes an extra 10 seconds to scan. It's another when you've got a family of 10 people and the dad is standing there switching between people, then each one has trouble scanning, he duplicates instead of finding them all, etc.But a person with a short rope isn’t just going to go off specifically due to a party’s ticket media taking longer than average because there’s a slew of other similar and typical minor disruptions with equal potential to set them off. It’s not the ticket media, it’s the person.
It sounds like a stupid concern until you're stuck behind it, and I'm not the only one commenting that it's a problem.