Why is D unpopular?

[kdevel]

On Sunday, 22 May 2022 at 22:59:25 UTC, Walter Bright wrote:
> On 5/22/2022 2:33 AM, Max Samukha wrote:
>> [...] many systems using plugins try to recover from bugs in a 
>> plugin.
>> In a sense, the plugin itself becomes an input that the host 
>> has to
>> validate.
>
> This is a faulty system design. There's nothing stopping 
> modules from corrupting the memory of the caller.

True.

> The correct approach is to run those modules as separate
> processes, where they can only corrupt themselves. It's why 
> operating systems support processes and interprocess 
> communications.

Why is this so rarely done? According to my experience one can 
use the ssh or the curl binary in a subprocess instead of using 
the libssh/libcurl in the caller's address space.

Apropos cURL: When eyeballing 
https://dlang.org/phobos/etc_c_curl.html I discern nothing. The 
same goes for https://dlang.org/phobos/etc_c_sqlite3.html both 
start with an unfathomable cloud of symbols. There is no 
structure, there are no concepts. I think both components are 
good candidates for using their binaries in a subprocess instead 
of pulling their library code into the own address space.