Emacs is in many ways anti-Unix-philosophy and I think the way it’s software tends to be structured is no exception. Functions can get ad-hoc extensions or modifications all over the place with advice and hooks and dynamic scoping[1]. The only similarity is that in Unix most things are files and in Emacs most things are buffers.

[1] Unix has weird ad-hoc mechanisms too like environment variables or your PATH containing modified versions of programs, and it has programs that do a thousand and one things, but I claim those are mostly violations of the Unix philosophy.

The Unix philosophy includes the use of software libraries in one's programs, albeit only resorted to when truly necessary. That often involves resorting to many of these tricks, usually for the sake of greater software reuse.

A philosophy that is cargo cult, as it was hardly ever followed on commercial UNIX systems.

I agree that they handle some amount of unix philosophy intuitively. But, for example, lots of command line programs don't handle SIGPIPE.