Business would be better named "pampering giant babies", because that's what it is. Despite the mythology that we're programmed with, most of the work of being in charge is managing peoples' feelings so that they stay favorable to you. There is a ton of room for mistakes as long as everyone likes you, and very little if nobody does. Thus, the whole of business training can be summarized with "be as popular and well-liked as possible". They try to dress it up fancy and act like they do something better than that, but they don't.
The most important thing in anyone's career is what their boss and their boss's bosses think of them. Only slightly less important is what their peers think of them. Work performance is essentially a non-factor in career advancement, so it actually is really important to manage this kind of thing carefully.
Asking directly for a raise is confrontational and inelegant. Subtly demonstrating that you deserve a raise and making your boss believe it was his idea is how you actually get one without alienating anyone. That's a lot of work, so most people just jump to another employer instead.