Bad guys can be great leaders, Osama Bin Laden is proof of that, but being a great leader doesn't necessarily mean that people are going to be considered as "great." Bin Laden and Hitler were both incredibly great leaders, but neither of them are looked at as great. Alexander was looked at as great both during and after his time, while a small few saw Hitler and Bin Laden as great, they are looked back on as evil to the point where people almost dehumanize them. Alexander was dehumanized in the way of being divine. I think the way in which we are dehumanizing these very similar people says something about the way people see thing today vs. how they did then.