Why are static classes considered “classes” and “reference types”?

Question

I’ve been pondering about the C# and CIL type system today and I’ve started to wonder why static classes are considered classes. There are many ways in which they are not really

Answer 1

What about static constructors? I think this is another important aspect to consider in your comparison. Classes and structs support them but interfaces and namespaces do not.

Construction implies instantiation. While the implementation may not actually create an "instance" of a static class, you could view static classes as a singleton instance of a class, to which there can only ever be one reference (the typename itself). If you could inherit static classes, you would break the singleton notion. If you could declare variables of the type, you might expect them to be cleaned up by the garbage collector when they are no longer referenced.

Why are they classes instead of structs? When I think of structs (value types), I think about values on the stack. Their existence is (typically) very short and they are copied frequently. This again breaks the single reference singleton notion above.