Is `alias this` a mistake?

[IGotD-]

On Tuesday, 3 August 2021 at 15:52:07 UTC, NonNull wrote:
> Here, further down, I just saw Walter indicate his opinion that 
> `alias this` is a mistake. Any thoughts?
>
> https://news.ycombinator.com/item?id=28029184

Usually inheritance can be replaced with composition and alias 
this has been the way to do that. Instad of alias this, Walter 
wants us to use mixin templates for composition. I have no 
problems with this but the documentation and marketing has 
totally failed regarding this few seem to know about mixin 
templates its usage and limitations. The D community needs to be 
market mixin templates better.