Earlier quoted context omitted.
More type theory heaviness === grand compile time. There is a natural correlation. Go chooses dev efficiency here over comprehensive type checking.
I think minimizing compile time is a weird metric to prioritize. It's essentially asking "Would I rather guarantee my program is more correct or save a few seconds each time I compile?" I would also point out that not forbidding bugs that would be caught by a type-checker will decrease efficiency. You just won't realize it when it happens. Lastly, the impact on compile time doesn't have to be so great to be problemat…
Iterating faster is also a way to improve the odds your program is correct.