You're confusing "it should be easy to stay in the lines" with "it should be very cumbersome to draw outside the lines".
Its trivial to bump versions in countless package managers but its frustrating in Go. Telling this dev that he's holding it wrong seems like undue push back. Why should this be cumbersome? I don't think accidentally taking major versions is a problem in most package managers.
It's bad to design the language to make it convenient for newbies in a way that makes it painful forever once you've written a nontrivial amount of code. Put newbie hacks in a playground where they belong.
Its trivial to bump versions in countless package managers but its frustrating in Go. Telling this dev that he's holding it wrong seems like undue push back. Why should this be cumbersome? I don't think accidentally taking major versions is a problem in most package managers.