Hasn't everybody and their mums/dads by now?
And even so, is that language succesful - to the extend that it means his ideas are more relevant that Rust's designers?
It's just a concept implementation at the moment, not a real industry / production / community language.
Johnathan Blow is a game designer, though.
At the end of the day he's someone who do write software for a living since decades, and has strong opinions and expectations. And he's using this to create the tools he wants to have.
Regardless of that, this is not a discussion about compilers or compiler design/programming, but rather about PL design, which are two different areas and disciplines.
The problem is that, ultimately, he's effectively throwing rocks from a glass house, but he denies us the rocks to throw back.
I just can't take him seriously.
He has designed a programming language, so it seems fair to assume he'd have an understanding of programming language design.