In my view many if not most professors are "careerists" in the sense that they put advancement of their career over accuracy. I wouldn't quite say that you need

In my view many if not most professors are "careerists" in the sense that they put advancement of their career over accuracy. I wouldn't quite say that you need to be really smart to make progress in most fields, though being smart helps. If you can do a lot of work often you can get a great result without being a supergenius. Ultimately it's much easier to fool reviewers than to do good research. I think most researchers are somewhat innocent in the sense that they produce bad research without knowing it's bad. Many of these folks seem apathetic to the quality of research, as you found in the professor who said they don't have time to go through the literature. As far as I'm concerned, if you don't have time to go through the literature (at a reasonable level, i.e., more than is typical now), you don't have time to do research at all.