The Go team has admitted several errors publicly (e.g. var binding for range loops, some standard library design) on multiple occasions. Those errors won't be c

The Go team has admitted several errors publicly (e.g. var binding for range loops, some standard library design) on multiple occasions. Those errors won't be changed because we consider preserving backward compatibility more important. You could say that holding on to backward compatibility is "defensiveness and stubbornness", but it's really just making a different decision to what you may have done in the same situation. In fact, your premise is almost entirely incorrect. Probably 95% of Go's language design happened before it was open sourced, so it's in exactly the same situation as Swift. The Go language hasn't changed a lot since November 2009.