[author of the article]

The RTL dump format does look a lot like Lisp, FWIW; see: https://gcc.gnu.org/onlinedocs/gccint/RTL.html or this article I wrote a while back on it: http://developerblog.redhat.com/2014/09/16/improving-gccs-in...

(This aspect of GCC is probably the oldest, written by RMS back in the late 1980s, I believe).

Middlebrow dismissal? Memory management is a common concern across languages, and languages which do not include garbage collection tend to host a variety of approaches depending on the author and what sort of thing they were building. Writing C code that uses garbage collection does not equal Common Lisp.

Not meant as a dismissal at all. I just noted that the phenomenon in which big complex C programs evolve into using features of higher level languages (like garbage collection instead of the regular malloc+free approach) is well known. Games are famous for using frame-bound arenas.

GCC wanted to run on anything that had enough RAM, so it's written in C (and now I think C++). I think a language with garbage collection and ML style pattern matching would be nicer for writing a compiler, and I don't think porting the GC runtime to every platform is that much work, but Microsoft didn't rewrite their compilers in F# and Oracle didn't rewrite the Java compilers in Scala, so maybe I'm missing something.

First, it's easier often to opt in to higher level functionality when useful then to opt out of high level language features. As for why no one ported compilers yet... that's a ton of work, even if they wanted to, for no benefit.