The problem is that the rules are broad enough that many sites could be construed to be breaking them leaving you up to Amazon's whimsy in enforcing them.
What happened with wikileaks, however, is a extraordinarily high profile controversy. It was material of very questionable legality, and material whose presence has lead to very serious cyber attacks. It is not reasonable to expect any 3rd party host like amazon to defend this "type" of free speech to the point of exposing themselves to huge risks.