D as a Better C

[Moritz Maxeiner via Digitalmars-d-announce]

On Wednesday, 23 August 2017 at 13:12:04 UTC, Mike Parker wrote:
> To coincide with the improvements to -betterC in the upcoming 
> DMD 2.076, Walter has published a new article on the D blog 
> about what it is and why to use it. A fun read. And I'm 
> personally happy to see the love this feature is getting. I 
> have a project I'd like to use it with if I can ever make the 
> time for it!
>
> The blog:
>
> https://dlang.org/blog/2017/08/23/d-as-a-better-c/
>
> Reddit:
> https://www.reddit.com/r/programming/comments/6viswu/d_as_a_better_c/

Interesting article, though one thing that I'm confused by is

>> Hence D libraries remain inaccessible to C programs, and 
>> chimera programs (a mix of C and D) are not practical. One 
>> cannot pragmatically “try out” D by add D modules to an 
>> existing C program.

I've been mixing C and full D for a while now (on Linux) by 
either having the main C program call rt_init/rt_term directly 
(if druntime is linked in when building a mixed C/D application), 
or have Runtime.initialize/Runtime.terminate be called from D via 
some plugin_load/plugin_unload functionality when using D shared 
libraries.
Why is this not considered practical?