There is some mental dissonance however, as I imagine this train of thought would be "obvious" to those in power, yet we see regular evidence of wage stagnation/suppression. If we don't assume incompetence, some optimum of balancing pay and churn has been found and accepted, and if I trust that they are making a self interested decision, there may NOT be a benefit to paying more. However, I'd really like to see the numbers, because my following intuition from a long time of watching the best engineers hop from job to job is that I probably wouldn't agree with their choice of calculations.
You are lucky to be working in an industry with a position and skillset that allows you that luxury. And yes it is a luxury, and one that many employees don't have.
However, like you say, it has to do wonders for corporate culture! (ignoring the jealous folks who think they deserve to be paid more than a janitor. I believe I remember a few such people when I originally read this announcement)
Obviously this is a simplification / wishful thinking. But maybe it's what we should strive towards :)