I think it has to do with intellectual honesty. There’s a lot of highly intelligent people who are willing to accept the status quo, even if they are aware that it’s broken, and just move on with their life. Then there are some people who are just psychologically incapable of such “ignore it and move on” attitude. Interestingly, this applies across broad spectrum of disciplines.
Science: A former kind of person does all the steps from a scientific method textbook and move on with their research. The latter kind of person won’t be able to avoid thinking about why the method is as it is, whether its rationale matches their experiment, whether there are special circumstances that make the method inadequate and so on.
Engineering: The former type of person would just take existing tools and practices, glue them together and get a viable product. The latter kind of person will agonize over corner cases, whether there’s a fundamentally different way of doing the same thing, whether the design is internally consistent and so on.
Arts: The former type of person is a mannerist. They use the existing expressive repertoire of their time and use it to create viable art. The latter kind of person cannot avoid seeing the problems with the current style, trying different ways of addressing them, getting back to basics and so on. Think van Gogh, for example.
Funny that I had exactly the same thought when writing the comment above: Isn’t that just OCD? But if you look at concrete examples, it doesn’t feel like that. Einstein? Incapable of accepting easy solutions? Yes. OCD? Probably not. Even van Gogh, despite the host of psychological problems, probably haven’t had OCD.