Can you share your impressions of the US-educated engineers/other STEM professionals with whom you’ve interacted whose merit for admission to their college or university might be in question? Have you noticed a greater variability in the quality of US-educated engineers vs. those educated only on merit (as you define it) somewhere else? IOW, is there a problem?
If not, then why is it on its face problematic that schools look beyond a bundle of evaluative criteria (of which you and most of us approve) to learn more about the person they’re admitting to their community? It’s going to happen when you interview for jobs, I can promise you. And, as much as I hate to say this, you will be evaluated on criteria that will make the criteria typically considered by admissions people seem entirely benevolent by comparison. In fact, in your professional career, I’d bet $100,000 that you will be evaluated, for the better or worse, on criteria that would be legally actionable if you could prove it (which you probably won’t be able to do): height, weight, appearance, gender, manner of dress, perceived socio-economic background, observable disability … and of course the ever elusive catch-all of “how well you present yourself.” I’ve seen it all make its way in, albeit in the most subtle manner. The world is a tough place.
So if I’ve got a kid who fits the bill with the top-order criterial, and one of them just outshines the other in some other way, why can’t I pick the shiny one? Again, that’s how the world mostly works. If you want pure objectivity with no favorites or “soft considerations”, I’d go with Track & Field: the stopwatch and the measuring tape don’t lie.