Just because someone is clear and cut "the bad guy" does not making people opposing them "the good guy". When someone is destined to stop the bad guy even at the cost of innocents if necessary that makes them pretty grey, not the good guy and also not necessarily the bad guy either. I think the meaning of grey has been warped by dumbass blizzard calling Sylvanas that to try and deflect at start of BFA? But no one is saying they are evil if that's what you're getting at. They are literally eco terrorists, just because it's done with good intent doesn't change the 2nd part of the equation, hence grey.