I love the wood elves. I even have an army of them ready to go, but since they straight up skin trespassers and hang it as a warning to stay out of their forest (in their novels) I think it's safe to say that the tomb kings are not evil for defending their lands either.
You can argue that the wood elves have more right because they really do need to keep people out of the forest but the goal of the tomb kings to defeat death was equally "worthy" and only time would prove it "wrong".