C interop is not as much a "killer feature" as it used to be. When you deal with data science, web and other similar domains, reading and writing JSON ergonomically is much more important than being able to call a C function directly. It's just a nice-to-have.
Yeah, but when you're doing systems programming (which Zig aims at if I understand correctly), easy interop with C is much more important than easy JSON marshalling.
