There are non-full-stack programmers? That's a scary thought. I have trouble imagining what sort of mind could be able to write code, but only one kind of code.
There are really two types of coders: the scrappy Ill-figure-it-out-as-I-go-along full-stack coders, and the Im-working-9-to-5-and-have-50-certifications coders.
Of course I exaggerate a bit, but businesses like to put people in little boxes. That means that the vast majority of business programmers (which are most of them) are working in one specialized area. They can write code, but don't know how the database works. Or they can make a kick-ass website, but have no idea how the back-end works. They can make the best library you ever saw, but they have no people skills. It's very common.
In fact, "full stack" to me means making things people want, which includes a lot more than just bits and bytes. It starts with words coming out of somebody's mouth and ends with them being happy. Lots of little steps in between.
