But the difference is: Your shader will be very special, working on a certain amount of lights and on one platform only. The abstract node based way supports different platforms.

Besides that it is not only a programmer vs. artist point of view like you mentioned. The Vision engine as an example also has a dedicated low level shader editor aimed to programmers with a good shader code editor (with 3 pages for global settings of the library, vertex and pixel shader). There are pannels forthe shader library files of the engine, panels for global shader properties, enlisted effect hierarchies and a real-time preview of course.

Besides that they recommend to also load shaders from artists into this low level editor later for optimizations. So it is not an artist vs. programmers story, it is often a story of collaboration.

Anyway, most projects especially indie projects will not create many custom shaders on their own. All the basic shaders are already included (yes, terrain shaders as well). And there are good reasons for that.