Why are arrays covariant but generics are invariant?

Question

From Effective Java by Joshua Bloch,

1. Arrays differ from generic type in two important ways. First arrays are covariant. Generics are invariant.

2. Cov

Answer 1

Generics are invariant: from JSL 4.10:

...Subtyping does not extend through generic types: T <: U does not imply that C <: C ...

and a few lines further, JLS also explains that
Arrays are covariant (first bullet):

4.10.3 Subtyping among Array Types