As someone who is regular Go programmer, yes struct tags do suck. It gets even worse if you want to try and combine multiple "annotations" into one struct tag string.

The reason its like that is that Go philosophically is very much against the idea of annotations and macros, and very strongly about the idea of a clear upfront control flow, and this is one of the reasons I love the language. But it does come at the cost of a few highly useful usecases for annotations (like mapping JSON and XML, etc.) becoming obtuse to use.

The idea of more compile-time macros in Go is interesting to me, but at the same time the ease of debugging and understanding the Go control flow in my programs is one of the reasons I love it so much, and I would not want to invite the possibility of "magic" web frameworks that would inevitably result from more metaprogramming ability in Go. So I guess I'm prepared to live with this consequence. :/