No, he is not and I didn't want to make it sound like I see that differently. For all the great things Rastakhan may have achieved and no matter how likeable and badass he is, at the point in time we meet him, he is a bad king. Bad for his empire and bad for the world. I still wouldn't have wanted him to die and rather they had resolved it differently, but I'm not sure if something like this is even possible within the scope of the writers or even in their intent. There's only two ways things can go if you screw up badly in Wow. Either become a raidboss and die or repent and be forgiven by the Light. Going through some soul-searching, finding out what went wrong and then actually tackle your problems and facing consequences is not an option. Oh, unless facing the consequences means you die and someone else cleans up your mess afterwards.