Let's consider the times when these institutions have had meritocratic admissions. What exactly have the meritorious students from these institutions contributed to society? The primary accomplishment is that they've engineered a corporate take over of society. The 2008 financial crisis, the tech driven surveillance society, all came from the talented minds of the merited elite.
So it is any surprise that there is support for the idea that merit is a meaningless idea? The gifted class hasn't made life any better for the rest of the society.