I don't know if I wholly agree. These are good questions with regards to language design. But for some people there is a massive learning experience that come

I don't know if I wholly agree. These are good questions with regards to language design. But for some people there is a massive learning experience that comes from designing and implementing a programming language and it's compiler even if it never becomes a successful or popular language. I feel this learning experience is has plenty of value even if the end resulting language does not. Anders Heljiberg wrote Turbo Pascal, J++, and Delphi, before moving on to things more widely accepted as successful like C# and Typescript. Yes Turbo Pascal and Delphi had some large followings Likely his experience from previous programming languages allowed to him be successful later.