Except that we put Garrosh on trial and argued over whether or not to execute him over his actions during the Pandaren Campaign, actions Sylvanas has sprinted past and left in the dust. "Everything is allowed in war!!! hurrrr" is an awful defense for genocide and you'd think that the Horde (whose members have largely been the victims of genocide at one point or another in recent memory) would stop and reconsider why they're so willing to defend it.