Why the heck is not possible using Custom Shaders inside a Material inspector?

Was that so hard allowing to create a Material Prefab using a custom shader? Is there any way to do that or I simply limite to create a new Material using c#? how many years unity were around and such a simple feature still not available? O_O

The shader will just fall under one of the Material Drop down menus. Look at the top line of a shader

Shader "UI/Magic" {   // this shader will be under UI dropdown menu

It was not documented anywhere. (or anywhere reachable by search engines by the way)