You still did not get my point:

If a 16-year old ambitious boy starts to develop a game, he will learn a node based shader editor much faster than HLSL. He does not need to know the math behind it, how to format a variable, how to define a scalar, a vector, whatever. He does not know about what mathematical operation is faster compared to another and so on. He connects some nodes. And that is easier to understand. Because of that, they dont like to learn another programming language. There are alternatives.

Besides that small casual games like Carboom have a limited audience. It does not make sense to learn different languages and to write so much shaders. I know that you did not learn it in a few days. You gathered a lot of deep knowledge, hints and experience over years.
But to earn money with such a game, you have to finish it in a few months, just because such games bring only a couple of thousand dollars. But if such a game will be released on Windows only, it will probably sell even worse. It could make sense on mobile phones though.

Because of that you will not find many casual developers writing their own shaders. The other ones like Slin will find a dedicated job sooner or later in a game company and will write shader only there.

This tells us a lot. It will keep hard to convince hobby developers to write their own shader. You tried that a lot in the past. But when you convince somebody to write them and he will dive deep into this world, he will probably not finish a game but become a shader expert. If such an expert is willing to look into more than only Gamestudio. If he is similar to Slin, who looked into Irrlicht, Unity or iOS, then he has a a good chance to find a job in the industry.

This is acutally how the reality works.