What are the prominent downsides of the D programming language?

[mw]

On Wednesday, 30 September 2020 at 00:13:31 UTC, Walter Bright 
wrote:
> On 9/29/2020 2:56 AM, Petar Kirov [ZombineDev] wrote:
>> I don't have experience with multiple inheritance in Eiffel, 
>> but it would be shame that in a language with `static if`, 
>> `mixin template`s, `static foreach`, etc. we can't figure out 
>> a way to make it work.
>
> The more interesting question is "is it worthwhile to make it 
> work?" No.
>
> Too many paths to implicit conversions (and that's really what 
> MI is) leads to nothing but confusion.
>
> (Besides, if we did, we'd break existing code that uses alias 
> this.)

I'm fine, if D just stick with single inheritance, just as Java 
did.

But the problem here is (as we discussed many times): currently 
with multiple interface, (multiple) mixin, (multiple) subtyping, 
multiple inheritance *has* crept into D *already*, and in a 
broken way.

If we have a *broken* effective multiple inheritance already, why 
not have a *proper* multiple inheritance instead.