This is the kind of tradeoff I'd be happy to see colleges worried about. Complicating the fact is that US universities generally don't expect students to be set on a specific major while European ones do, making the US problem a bit harder. But I don't think this is what US unis are trading off on. I think they're trading off merit for parental wealth + future wealth (which is greatly effected by parental wealth).
Re: your comment about different unis with different criteria, I'd be a lot less worried if the diversity was evenly distributed geographically. I had the privilege of being able to choose from multiple countries. For the vast majority of high school students, studying abroad is not an option.
"US unis" don't seem like a homogenous block to me. But then, I went to a state school and received a fantastic CSc education that I would not trade for ivy league at any price. I've also interviewed/hired countless people and never even noticed what school they came from. I guess the policies of Yale don't bother me that much either way.
I feel like you're expecting some sort of clear stack ranking of students. Even if you take tests at face value, do you accept the student who aces math but bombs literature, or the student who is merely above average in both? See also: computer science, chemistry, biology, physics, history, physical fitness, social sciences, languages, music, art...
We have examples of test-regime-driven educational advancement in Asia. From what I've read, it doesn't seem very appealing to me, either as a student or as a parent.