Oh I think that’s an accurate statement, although there are debates on other forums about whether UChicago students today are as committed to “life of the mind” as their elders were in another generation. But it’s an odd claim that love of learning can be correlated with little to no measure of performance. I think MIT is an exception with their particular policy; in general, liberal P/NP/NC policies tend to be associated with lack of seriousness and with reduced effort, particularly in the liberal arts. It’s associated with doing C- work. I’d argue that to introduce such a policy would conflict with UChicago’s own goal of providing a rigorous liberal education.
UChicago does indeed allow for P/NP to be worked out by the instructor and the student, and it applies mostly to electives. Core courses, which really make up a good chunk of the students’ first couple of years, must be taken for a quality grade, and many of those courses are pre-reqs for study in the major, with additional academic performance thresholds there. Grade policies within the major are set by the academic departments overseeing the program; some may, indeed, allow for a P/NP or two but it’s not typical. My two kids are in non-STEM/non-Econ majors and neither allows for P/NP, although one of them says that a student may petition in “exceptional circumstances.”