Just as you're not arguing to use C for everything, people liking high-level languages aren't arguing you should never use C (or, at the very least, a similarly low-level language).
Rather, the point is that using C is very often a premature optimization. It also comes with a sacrifice in terms of productivity, maintainability, safety, testability and readability.
So you should certainly use C. Sometimes. And the question to ask is always: "why C?" and never "why not C?".
Also, you can get quite far by doing something like generating C from a DSL embedded in OCaml or Haskell, giving you both powerful type-level features and many of the advantages of a high-level language without sacrificing low-level control of C. You could use something like CIL[1] to avoid many of C's usual pitfalls. I haven't tried this myself, but I know some people happy with that approach.
This person argued that the only way to make progress in systems programming is to ditch C as the basis of the system and linking model, in favor of something more constrained. That's the kind of talk that gets me cranky. It's precisely because C and assembly are so unconstrained that such a wide variety of programming paradigms can all be implemented efficiently and run under a single OS, and that we can so easily experiment with brand new paradigms without having to get buy-in from the VM gatekeepers.
Rather, the point is that using C is very often a premature optimization. It also comes with a sacrifice in terms of productivity, maintainability, safety, testability and readability.
So you should certainly use C. Sometimes. And the question to ask is always: "why C?" and never "why not C?".
Also, you can get quite far by doing something like generating C from a DSL embedded in OCaml or Haskell, giving you both powerful type-level features and many of the advantages of a high-level language without sacrificing low-level control of C. You could use something like CIL[1] to avoid many of C's usual pitfalls. I haven't tried this myself, but I know some people happy with that approach.
[1]: http://www.cs.berkeley.edu/~necula/cil/index.html