They had a chance to cure C's lack of type system and they consciously decided not to do it. Which kinds of makes it just a garbage collected C with some extra syntax for channels.
The creators are big time RESPECTED UNIX HACKERS who insist on doing everything in an archaic, unconventional way, as though this made them more rugged. "Everything should be as simple as possible, but not simpler." They just leave out major important features from Go in an attempt to make the language "more simple." Sure, the complexity of Sepples is annoying. Simple tools are reliable and easy to use--but toothpicks are also simple, and I'm not going to use toothpicks to build a skyscraper. In other words, Go is ideal for toy programs.