If every generally careless pilot was quickly eliminated from the gene pool then I would agree with you. However, whilst professional pilots are probably selected to be conscientious by other routes such as failed checkrides, I'm not certain that the same is true for private pilots - all we have to do is fly reasonably consistently for the examiner, on one occasion early in our flying careers. How much or how little we do after that, is largely down to us. (I'm currently a student PPL)
As far as I can tell, the only defining characteristic of a private pilot is to be reasonably well off, which generally implies a pre-existing and reasonably high level of intelligence and discipline in our professional lives.
After that, as pilots we all enjoy flying, or wanted to do so at some time in the past. It may be that the original dream was doing slow rolls low over the countryside in a Tiger Moth, or zooming and booming down the Welsh valleys. The reality, as I experience it, is far more down to understanding how a multitude of systems work and interact - from carburettors to cumulonimbus clouds to navigation. I enjoy this immensely - the neuroscientist Simon Baron Cohen would definitely rank me fairly high as a 'systematiser'. As such, I dislike having gaps in my knowledge and try to fill them whenever I can. A reasonably high proportion of pilots seem to have technical jobs or hobbies - I know a fair number of physicists or programmers who are also pilots so I think this is a common and probably desirable characteristic, but not a defining one.
Finally, I enjoy making important decisions - sometimes under pressure. There's a degree of honesty about flying - if something goes wrong, you risk getting killed, whether or not it was you that made the fatal mistake. However, I often wonder how apparent this sense of jeopardy is to other people. I hurt myself mildly in a hang-gliding accident a few years back but look back fondly on my hang-gliding days. It was a very immediate way of flying - you're out there with the wind rushing past your face, and you're at a reasonably low level most of the time. Flying in an enclosed light aircraft is a very different experience. You sit there in a warm bubble, and although you see the scenery go by and know that you're flying incredibly high and fast by comparison, the sense of jeopardy isn't nearly as visceral. I do know a few pilots who simply don't seem to feel it.
So all in all, I'm not sure that it's so easy to pigeonhole pilots. On the other hand, as is probably clear I like to think that I have a better understanding of systems than many people, and a greater awareness of risk. As I read over my post, I have to admit there's probably a degree of self-confidence/arrogance there. But as the psychologists argue, humans are inherently incapable of honest self-appraisal, so whether or not it's warranted is another matter.