D can be used for almost everything: this is indeed a marketing message that is harder to pass than "Language X is made for problem Y".

For example I do signal processing, and D is surprinsingly pleasant for it since it has builtin complex numbers.

Being well-balanced, generic, readable, productive, and performant seemingly doesn't convince more than "this solves problem Y". Probably why marketers use segmentation.

But at the end of the day, more power is more power and every specialized language tend to become general-purpose.