Because they aren't copies, they simply have similar designs. By your logic, I suppose Microsoft could sue Apple since Windows Mobile had an applications list.

Exactly. They aren't copies.

But MS suing Apple - I don't think my logic has any such implication or connotation.

As pointed out in Nilay Patel's article, TouchWiz is an attempt to mimic iPhone look & feel.

If Samsung had evolved their original design, which you had pointed out was not a copy, then it is a different story.