I think the history of D having a garbage collector (and arguably exceptions / RTTI) from the beginning really cemented its fate. We all know that there's a "BetterC" mode that turns it off - but because the D ecosystem initially started with the GC-ed runtime, most of the D code written so far (including most of the standard library) isn't compatible with this at all.

If D really wants to compete with others for a "better C replacement", I think the language might need some kind of big overhaul (a re-launch?). It's evident that there's a smaller, more beautiful language that can potentially be born from D, but in order for this language to succeed it needs to trim down all the baggage that comes from its GC-managed past. I think the best place to start is to properly remove GC / exception handling / RTTI from the languge cleanly, rewrite the standard library to work with BetterC mode, and probably also change the name to something else (needs a re-brand...)