Ahh, if we are comparing equivalent implementations, you are definitely correct. GC and goroutines are much more complex than anything in C. In fact, off the top of my head, the only features truly missing in Go from C are unions (unfortunately) and the preprocessor (effectively a part of C).
There is a big difference between implementing them for fun and implementing them for a production system. Regardless, even if they are simple to implement they are more than what C90 has so, by definition, more complex implementation.
