Inherent code performance advantages of D over C?

[John Colvin]

On Friday, 6 December 2013 at 23:56:39 UTC, H. S. Teoh wrote:
>
> It would be nice to decouple Phobos modules more. A *lot* more.

Why? I've seen this point made several times and I can't 
understand why this is an important concern.

I see the interplay between phobos modules as good, it saves 
reinventing the wheel all over the place, making for a smaller, 
cleaner standard library.

Am I missing something fundamental here?