Treating a context value as a bag to fetch data out of is the first mistake. They should only ever be used to control things like deadlines and whether or not a part of a function executes. IMHO they should disallow attaching values to a context.
Yes/no/maybe? context is one of the few ways to get contextual logging and tracing to work in a almost general way in Go. But I have also used it to pass the authenticated user to the handlerfunc. I dont dig it, but it works and avoids the need to keep a static map of request pointers somewhere to figure out which user was in this request...
