I guess it's a matter of preference -- programmer versus artist. I'd no sooner choose to click together a shader over writing one than click together a game rather than make something original.

Node-based is great for simple materials. Engines that provide such a system make it easy to meet some industry standards. But what is one to do when they want a multi-texture shader where some layers cast some shadows on others, some layers have true reflections, and so on?

Writing one's own shaders is good for performance, as well. Even for a more standard multi-texture shader, if only two layers need a specular map, I'll write a shader that only uses a spec map for those two layers.

Even the simple stuff I do differently every time for different projects. Maybe in one project I have an AO map, which will only affect ambient lighting, but in another project I can't be bothered and I bake AO into the diffuse texture. Or I might hard-code some hemispheric ambient lighting -- very little performance cost, but it can really add some shape to areas in shadow. These are simple, intuitive, artistic tweaks that aren't all going to be doable in a node-based editor.

I wouldn't start a project in another engine without learning to write my own shaders in that engine. Custom-made shaders get a better performance:prettiness ratio.

As it turns out, I also create shaders in minutes. And then I can spend hours tweaking them if I need to, adding things and changing things, and see the changes updated in real-time. Code is easy to reuse by modifying default.fx: I might have my own fog function that uses a cube-map rather than a single colour to get a good-looking atmospheric scattering effect in a sunset -- I'd write the function once and from then on call "niceFog(pos)" in any shader that uses it.

Jibb