The curriculum is tailored towards people of average intelligence, so if you are one, two, or three standard deviations above that, you won't be under pressure to develop a work ethic because you can get good grades without it.
Of course, if your intelligence is above average, then you probably are interested in a career that attracts other intelligent people.
And then you are in a serious trouble, because now you are in an environment where everyone is of similar intelligence, so you don't have your competitive advantage anymore, plus some people have a work ethic that you lack.
And even if you are still a standard deviation above most people, there are likely other people who are at the same level as you, and they might have a work ethic.
I think this is something that people who have intelligent children need to pay attention to.
Even after grad school, in industry, I’ve been much more of a strong executor than an idea generator.