The reason C beats Forth is code-sharing. Forth is a better language and system on its own, but it's difficult to standardize for reasons both technical and cultural. So if you write some really wonderful code in Forth to, say, decompress a bytestream, another Forth programmer is unlikely to be able to use that code without substantial modification. So Forth becomes either a single-person or a small-team system at best. Larger teams can't grow (in part because onboarding to your particular Forth system is a non-standard process), and especially cross-pollination between teams and companies is not possible.