From the viewpoint of the Alliance, Sylvanas abandoned Varian to die against a Horde of demons and Gul'dan. So not only did the Alliance have a way better Lok'tar Ogar, the Horde showed themselves to be cowards by and large. Genn attacking her ships, which I'm sure there is plenty of fanboi justifications, was most likely in retaliation for that. Lets be real here, Sylvanas' plan in Stormheim were just as nefarious as ever. There is no nobility or honor in the Horde while she is warchief.
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I cannot even begin to describe how flawed your logic is on this. It is like getting stabbed and then someone coming to dig in the wound, nothing good comes from that scenario. The Alliance is destroying the machines digging into the world of Azeroth to stop the Horde from making it worse...