It is how the night elves and tauren can be so friendly to each other with there druidic societies.
And be on opposite factions. Do the night elves blame the tauren for what Slyvanas did? Does malfurion kill them for being part of the horde and leader of druids?
Everyone’s character is not on the same boat, they dont share the same opinions.
My shaman might hate the kul tirans for what they did to my king. But still work with them as they have known good humans such as the undead, or fogsail kul tirans. Or my work helping nuetral factions such as the explorers league in Uldum. Heck nesingwary was right there in Zandalar where I could help him kill some dinos and save him from a head hunter.