I share the following to inform the public about one dynamic I know is occurring in higher education, and I presume might occur also in K-12 education.
I learned while teaching undergraduate and graduate students for sixteen years at Saint Louis University that an unspoken alliance is frequently made between faculty and students. Most university faculty in science departments at SLU were evaluated annually on three criteria – their scholarship/research productivity, number of courses they taught, and their service on University committees. In our department at SLU, research productivity accounted for the majority of a faculty’s evaluation, followed by teaching and then service. Salary increases and promotions were based in part on a faculty’s annual evaluations, thus most science faculty focused their time and effort on research, and limited their investment in teaching and service. This does not imply science teachers did not teach good courses; but rather they felt compelled to spend a majority of their time on research. This is true for most faculty in research-intensive universities.
If a faculty member chose to do so, he/she could readily boost their teaching evaluation(s) by making their classes entertaining and easy, which almost always resulted in favorable students’ evaluations and reduction in students’ complaints. The unholy alliance (which resulted in grade inflation) is that a professor offered an entertaining easy course. The students were given good grades for little effort. The faculty’s teaching/course were highly rated by happy students. Students graduated with higher GPA’s and honors. This is one reason why grade inflation is now rampant in higher education. (For example, 80% of students at Harvard are given an A or A+.) Obviously, this unholy alliance is detrimental to the education of students, and effectively deceives future employers and the public who believe high grades correlate with mastery of material.
I suspect the same unholy alliance also occurs, albeit to a lesser extent, at K-12 levels with the wrinkle that teachers probably try to minimize complaints from parents by not assigning low grades to their children.