] I think it is a reference to the particular circumstances, but also to the whole idea of human nature, original sin and the whole garden of Eden/paradise lost kind of motif that recurs.

I like this idea, Barb. So, to Hamlet, Denmark when his father was alive was an Eden, and then with the sin of regicide, came also a whole host of other sins: incest, covetousness, lying, theft, etc. Denmark is now without grace and has been cast out of Eden and into the outer darkness

Fie on't! ah fie! 'tis an unweeded garden,
That grows to seed; things rank and gross in nature
Possess it merely.