This makes sense for Go. A big part of the reason the generational hypothesis is true for most applications is that they allocate short-lived objects inside function bodies that are no longer needed when the function returns.

In Go, most of those objects actually do get allocated directly on the stack, or as fields directly inside other objects. So they are never seen by the GC. This is one of the aspects of the language design that I really admire.

Or, you could look at as saying that Go does have a generational memory manager, and the first generation is "on the stack".