The next proposed systems language should feature wide adoption.
Seriously, you haven't demonstrated anything that Go lacks besides users. Most languages are chosen not because of the language itself, but because of the libraries, tools, and support available. There needs to be an ecosystem for a language to have a chance at adoption.
I've also stated before that any new language can only succeed if it capitalizes on an emerging frontier in computingany new language can only succeed if it capitalizes on an emerging frontier in computing. I doubt systems programming is an emerging frontier, which may explain why D never experienced the success it may have had a few decades earlier.
I hate to be a pessimist when it comes to new programming languages, but I'm afraid that no new systems language will ever be successful.