I have written before about how selection for high Conscientiousness has come to dominate modern formal education - and especially colleges and universities:
One reason for this is likely to be the low motivation of most students at most higher education institutions.
This is an indirect consequence of massive government subsidies of higher education, which has grossly (and I mean grossly) distorted the provision of college and university education compared with its natural/ spontaneous market level of provision of just a few percent of the population.
(Ref: British Universities Past and Present by Robert Anderson, 2006)
Thus, most students at modern universities are merely there to get an educational certificate which signifies merely that they have been signed-on at some kind of institution and passed a certain number of evaluations.
In particular, for the vast majority of students in the vast majority of institutions there is no vocational, knowledge-and-skill-based or professional reason for the course of study; and (obviously!) a near-zero proportion of students are interested in the subject 'for its own sake'.
The result is students who are fundamentally unmotivated with respect to the ostensible subject being studied; and therefore a steady downward-pressure on educational standards and steadily-inflationary pressure on the value of qualifications - that is; the minimum of work, knowledge and skill for the highest graded qualification (and no failure) - as a by-product leading to inexorable lengthening of the educational process required to get any actually-useful education.
Conscientiousness can be seen as the ability to work hard and steadily despite lack of motivation - therefore, in the modern higher educational system where almost nobody is motivated - the ones who do best are those who can complete educational programs and evaluations despite an almost complete lack of motivation.
In contrast was my own undergraduate experience as a medical student, where the general level of motivation was high - people wanted to learn the stuff because they were going to be doctors.
This made a very large difference. Most lectures were mostly-full; and students would ask for extra teaching and training - including vacation, in the evenings and at weekends; form unofficial study groups - and, in general, push for more and better education.
On non-vocational courses, where the knowledge and skills have no direct ink with an anticipated job, none of this happens; but instead nothing is done that is not examined, and the general trend is to aim to do the least work for the best marks.
But the mass of people in the mass of institutions are fundamentally un-interested in what they are doing - uninterested in the sense that the subject has no intrinsic interest and also that they lack any personal bias or involvement in being good at the subject (ie.extra knowledge and skill does not bring any personal benefits, such as a safer or more successful career).
And when people are uninterested, then only the most Conscientious are able to make themselves work.