A few years ago the Intercollegiate Studies Institute did a survey of knowledge of American history among Harvard freshmen. They were retested four years later. They did worse as seniors than as freshmen. So yes, at least some universities are in the business of dumbing down their students.
It all began in the nineteen sixties when California (and New York!) parents who found their stupid kids could not get into a major university sent them away to Oregon. There they entered Oregon, Oregon State and Portland State. Those universities welcomed them as they welcomed the ‘out of state’ tuition foreigners were charged. It was because of this influx that one began to see signs, “Don’t Californicate Oregon.”
With the war in Viet Nam most people do not know that the University of Oregon became the center of the anti-war movement west of the Mississippi. The attacks on the U. of Oregon campus (on buildings and professors) occurred in greater number than at any campus anywhere in the USA. And the attacks were carried out in the main by students from out of state. Following the war, radicals discovered that quiet laissez faire Oregon was the perfect meeting ground for the dissemination of their anti-American propaganda. And the rest, as they say, is history.