Hi zorkw4rg. Thanks for having a look at the tutorials. What makes the vertex shader not readable in your opinion? If you substitute the different values gl_VertexID can take (0,1,2), it's not hard to calculate the values of gl_Position.
Its certainly not hard to calculate but a if this index then this vertex coordinates, and so on, seems significantly simpler than having to calculate anything at all? It sure what be more verbose though.