[crabbone]

The parent wasn't talking about backwards compatibility. They specifically mentioned forward compatibility. Something that requires continued maintenance effort, and the more versions you roll out, the bigger the effort.

I seriously doubt Go is advertised as forward compatible or that it is such in practice. Just like any similar programming language, they depend on system interfaces, and those change, albeit at a slow rate. If all older versions of Go aren't on life support, then some will become obsolete over time.