Very interesting explanation. One of the issues is that people who are willing to be beta testers are different than the normal user base. So issues don't get uncovered. I might find a workaround for an issue and not even report it (possibly because I was focusing on other things that are my pet peeves). Or, as a beta tester, I might be more likely to pay attention to a machine in its environment, and not push it beyond its limits. A regular operator might bounce the machine through the tough condition. So the engineers don't know to fix the problem. It gets into the normal retail base and becomes a big issue.