Comment by eksemplar

I think it’s easiest to explain like this.

You don’t get a lot of opportunities to earn a PhD, most people never get the chance. By comparison almost everyone in CS get a lot of truly great job opportunities in their lives.

That’s a PhD, we had a habit of hiring people before their finished they CS degrees because skilled people were so hard to come by back in the day. They have good careers as far as I know, but they would have had much better opportunities if they had finished their degrees, and some of them haven’t taken that well.