[jarrett]

One certainly could. But to obtain the same properties you get with Erlang, you'd have to reimplement some features of the Erlang VM: Lightweight threads, message passing, etc.. Erlang is opinionated. It imposes a very specific model of concurrency. If you buy into that model, the language/VM gives it to you for free. If you don't, then you pretty much can't use Erlang.

By contrast, C is a very low-level language that can do anything. You can implement any model of concurrency in C. But you'll be doing all the plumbing yourself, or using a library that does the same. Erlang's model is not the only possible way to be lock-free, and you can pursue other options in C, if you want to.