Care to explain why it's overused in comparison to other toolkits/frameworks/libraries? Taking in to account, of course, the target use-cases.

Along the same tone, httprouter doesn't allow defining these routes simultaneously

    users/:id
    users/watching

Was kind of surprised as we have many routes like that. Like gorilla/mux, I think it was just first (trie-based mux). Isn't gin based on httprouter?

There are even better muxes now. `pressly/chi` is used by heavy hitters in production and takes advantage of Go 1.7 HTTP context. `labstack/echo` is another highly recommended by others but I don't like the non-idiomatic echo.Context in handler signatures.

Back on topic, I hope the go web examples only imports built-in packages. The gorilla/mux example could easily be written to use built-in packages.

Part of the reason is that gorilla/mux uses identical API to the standard library.

I avoid httprouter because it doesn't adhere to the standard library interface for http handlers. I've not used gin, but it looks to also not follow the standard library interface here. Also, it does not appear to make use of newer developments in Go such as the context package (it imports the x/pkg version but does nothing with it I think).

I believe gorilla mux came out years before the others, so it's not really shocking that it is used more. I personally have never had any issues with it but to each there own.

Contradiction does not exist. :)