What are the prominent downsides of the D programming language?

[Ruby The Roobster]

On Monday, 21 September 2020 at 09:29:21 UTC, Tomcruisesmart 
wrote:
> Hi,
> I'm looking for healthy conversation.
> What are the prominent downsides of the D programming language?

One downside is that classes can't inherit from multiple classes. 
  I know that there is a thing called an interface which a class 
can inherit more that one of those. Thing is, functions in 
interfaces have to be abstract.  Also, member variables declared 
in an interface have to be static, and the only member functions 
that are defined have to be static. Why can't we just inherit 
from multiple classes?