Okay Go, why was this omitted?

When checking for the existence of a particular key in Go, the idiomatic way of doing things is this:

salary := make(map[string]uint)
.
.
.

_, ok := salary["Roger Goodell"]

if !ok {
   // value wasn't found
   salary["Roger Goodell"] = 68000000
} else {
   fmt.Println("Roger Goodell is not hurting for cash.")
}

Simple right? Well yes, but also horribly inconvenient. I don’t want to define an in-scope variable to determine if a key exists in the map; sometimes I might want to check and quickly branch off that logic.