Why Enum constructor can't have protected or public access modifier

Question

Enum constructors must be either private or package default, and protected or public access modifier is not allowed. Why so

Answer 1

Because an enum, by definition, has a fixed set of instances which are declared and constructed in the enum itself. Using the constructor from outside of the enum class itself thus doesn't make sense.

And AFAIK, an enum constructor is always, explicitely or implicitely, private.