The web GPU API and the lower-level API aren't "totally orthogonal" if you're using the Metal shader language in your web GPU API! You're trying get web authors to use (a part of) Metal! It's totally not orthogonal.
The shader language is partly independent of the API though, and we though the API was the interesting thing to prototype, more so than shaders.
The post was VERY clear that that was temporary while working on the other basics and a real decision would be made later.
Isn't this the way you're supposed to do open source? Post code early and often for comments?
It seems like a ridiculous requirement that to show a sketch of what they think a web API should look like for next generation 3-D graphics they should have to design an entire shader language that's different from the one they already have.
It's just a placeholder. They didn't even SHOW the language. They just referred to its name and said they were using that for expediency during the initial version of the document they were showing.
> should have to design an entire shader language that's different from the one they already have.
They don't need to design a new language - take existing open one and use it.
I think you're reading a lot of intention that isn't there into that placeholder.