I think it all comes down to the big difference between having a degree and being productive at a company, along with how free the labor market is. I have work

I think it all comes down to the big difference between having a degree and being productive at a company, along with how free the labor market is. I have worked at a few places that just didn't take people out of school at all, because they saw that the amount of time the typical graduate they got was a net negative to productivity, compared to how long people stayed at the company, didn't add up. They figured out that in their case, given their relative inability to tell the highly productive recent grads from those that would not be productive in a year, that it was better for them to spend resources paying experienced people really well, and letting other companies sort out the good and the bad. Thinking like that leads to some kind of farm system: People that are just body shops, where the good people manage to go to a next tier of company quality. A shortcut for this is a degree from a nice enough university, as there are many companies out there that will interview anyone coming from a prestigious university, but would not give the time of the day to a recent graduate from, say, Missouri Rolla. And let's not forget the madness that is interviewing in big tech companies. All of that 'optimizing to avoid false positives' idea is really saying that people that don't have a specific interviewing shape, but are very good when at a job, don't have a chance. I have a job at one of those tech companies, but some of my favorite developers from earlier in my career just can't pass the interviews, even though I think they are, in practice, better than your averaged hip company employee. So it all comes down to how we are terrible at figuring out good performance, and how training people just isn't a good economic decision when they can just leave to a place with a bigger budget in a year or two.