How about night elves, are they all xenophobic?
Thats right, as you try and typecast orcs into one catagory so you can understand them easily, I can do exactly the same to alliance races.
But unlike you, I know none of its true, since there are many characters in the lore who show they are not the sum of there supposed stereotype. Saurfang, Rexxar, Eitrigg, Gorgonna, Thrall, Aggra, Rehgar Earthfury, orcs of the earthen ring. With humans you have Anduin, Tirion, most of the argent crusade.
Just because you have characters like Garrosh and Varian floating around doesn't mean its the sum of all the race.