As has been said many times in this thread, the first time the Forsaken encountered the Alliance was when they met Garithos and his troops. The Alliance made a truce with the Forsaken, which the Forsaken promptly betrayed and killed them all. The Forsaken aren't some group of poor victims of human racism.Unprovoked? Seriously? I guess human leadership trying to evict them from their homes because they were "monsters" had nothing to do with feelings of resentment, eh?
The only reason Putress made a plague in the first place is because Sylvanas told him to make it. Putress' crime was acting out on his own and trying to seize power from Sylvanas while working with the Legion, but their ultimately goals weren't dissimilar.Don't mistake the rogue undead at the Wrath Gate to be representative of the Forsaken. They were actively fighting against Sylvanas and the Forsaken; it's hard to blame the Forsaken for the actions of those fighting against them. Further still, the Forsaken quickly rendered aid to Silvermoon in the Ghostlands. Sylvanas made it very clear: she hasn't lost any love she had for her homeland. This isn't characteristic of someone who wants to kill "all living creatures."