The main argument coming against it is not following the “Unix philosophy” which I’m a proponent for
Gosh, don’t use a “GNU’s Not Unix” system then!
I think you’re confused about what “Not Unix” means in the name “GNU’s Not Unix”. It’s nothing to do with the Unix philosophy. It’s to do with overcoming the limitations of proprietary Unices from the 1980’s. From the GNU Manifesto:
“GNU will be able to run Unix programs, but will not be identical to Unix. We will make all improvements that are convenient, based on our experience with other operating systems. In particular, we plan to have longer file names, file version numbers, a crashproof file system, file name completion perhaps, terminal-independent display support, and perhaps eventually a Lisp-based window system through which several Lisp programs and ordinary Unix programs can share a screen. Both C and Lisp will be available as system programming languages. We will try to support UUCP, MIT Chaosnet, and Internet protocols for communication.”