The first thing to come to mind is that selecting is simply much cheaper than grooming. If a company can get employees of roughly the same quality level without having to pay for an expensive grooming process over many years, they're going to do that. There's also less risk with selecting, because a groomed candidate can always decide to up and leave for another company (or die, or join a cult, or a have an epiphany and decide to live a simple life in the wilderness of Alaska, or whatever), and then the company is out all that grooming money. I feel as though groomed employees would have to be substantially better than selected ones to make up for these disadvantages.