You forget the fact that Go is a young language while modern C implementation has to support several standards, countless extensions and probably decades of cruft in the codebase. Additionally, if you factor in that go includes a tool that replaces most of what autotools gdoes in the C world, we're talking about a huge blob of accidentally complex code.
It's very reasonable to think that the Go implementation is simpler.
I'm not forgetting. The make tools are not part if the language and irrelevant. Most C developers I know avoid extensions for portability reasons. The cruft part doesn't matter much for this discussion either, you can start from scratch if you want like TCC. The language definition of Go requires some things that C does not for any reasonable implementation. I think it is much more reasonable to think a C implementation will be much simpler.
It's very reasonable to think that the Go implementation is simpler.