We don't have "meritocracy" already, so this isn't a useful objection.

And when you consider that companies constantly complain about how difficult it is to find, hire and retain good people, you'd think once they've found one they'd want to, y'know, actually work to retain that person long-term. That would, after all, be what a meritorious company would do, and by setting that example word would get round and other good people would want to work for them.

In fact, perhaps you should consider that your entire view of this is precisely the opposite way round of where it ought to be.