I'd love to see language design and language development treated as different disciplines.
Just like developers were the first web designers, developers have been the first language designers.
Ideally a language designer would only be tasked with how to express complex ideas in a simple, composable syntax.
Language developers would be tasked with everything else: basically making those ideas work as efficiently and consistently as possible.
Not to say a language designer and developer can't be the same person, but I think there might be some benefit to having a linguist (with some understanding of development) and a developer (with some understanding of linguistics) team up on a new language.