I would be careful drawing many conclusions from this study. Without putting the respondents in a simulator and actually seeing if the confidence is founded in reality, the study doesn’t actually tell us much. There are plenty of people who could probably land (or at least crash land) a plane with guidance in ideal circumstances. From my own experience learning in small planes, confidence has a huge impact on a pilots ability to execute a smooth landing. The first one is terrifying but you gain confidence with experience. Certainly if someone doesn’t think they can land a plane, they probably can’t and shouldn’t, but without testing it’s really hard to make factual statements about the those that think they can.