[skybrian]

You're right that reflection and compile time code generation are somewhat "dual" in the sense that you can often implement a feature using one or the other.

But that doesn't mean everyone should make the same choice. Go doesn't have macros or templates. It would make the language much larger and many Go development tools would have to be modified to deal with the complexity. This is a minimal language tweak that was far easier to implement, and devtools that don't care about tags can ignore them.