Git Town started out as Git aliases written in Bash. Version 3 was many hundred lines of Bash, pushing it beyond what Bash was designed for. At some point it got ridiculous, and we got requests for Windows support, as well as better integration with the Github API. Hence the rewrite in Go.
I still don't see the killer feature here. It just throws around ton of commands, most of which are completely unnecessary.
They had to write thousand lines of code in Go instead of these aliases. Startup aura!