It depends on what branch of CS you're in.

Just like computer science is not about computers, it's also not really about programming. Certainly there's overlap. I have a pH.D. student friend who works on proving the correctness of programs. He doesn't write code, he writes proofs. Of course he'd be more rusty in C than a full time C dev.

But I also have pH.D. students that build proof-of-concept software. Yeah, they're not optimized in the way that live software is optimized, but they can certainly code.

And I really have to wonder where you went to school if "most" of the TAs and profs "can't code" and what kind of standard you have. That was not my experience at all when I went to school.