All the time I see people giving Jaina and Genn shit for being "Warmongers", but their reasons for hating the Horde are fairly justified.
Jainas home got nuked, it might have been Garrosh, but the rest of the Horde let it happen, and it's hard to trust a faction that destroyed your home and killed your people.
Genn has his city destroyed and raided by the Forsaken, and his son killed by Sylvanas, with Sylvanas as the new Warchief, I can't imagine he'll want peace with the Horde.
Fairly good reasons. Then you have Sylvanas, who everyone seems to love, who just does whatever, essentially becoming like the Lich King. - "The difference warchief, is that I serve the Horde"
Garrosh who has his little fanclub, who was wrecking havoc because "muh orcish horde". The Horde are much worse for instigating war, yet its Jaiana and Genn who get criticized for holding some pretty justified grudges.