I see D as a non-compromising language (in terms of eating your cake and having it too) and that's why I like it. I think the authors don't want to limit its pe

I see D as a non-compromising language (in terms of eating your cake and having it too) and that's why I like it. I think the authors don't want to limit its performance at the design level. For equivalent code, they don't want it to only ever be able to run 99% as fast as C, they want it to be able to run, at least theoretically, as fast as C or better. That's probably where the 'systems language' comparison came from. In practice though, I'm willing to bet DMD,GDC and LDC result in more than 1% difference in performance (but that's just speculation).