Why? Go doesn't really offer a whole lot in terms of security, except for better managed memory. I'm not even sure you could reliably eliminate side channel attacks in Go.
What makes it better? Haskell's GC is very advanced.
Better than C, that is. Haskell is on a whole 'nother level of "what are memory bugs?"
http://hackage.haskell.org/package/base-4.7.0.0/docs/Foreign...
What makes it better? Haskell's GC is very advanced.