Yes. Ending several conversations with "or you will be killed." doesn't really portray a lot of sympathy.
I think there's a subtle difference between evil for one's self and evil in a cause. The latter can be arguable, as we've seen people try to do in our time. Kor doesn't seem
as evil because he isn't doing it all for himself but for the Klingon Empire as well as his portrayal as being personable. Actually, that freindliness to Kirk makes him more dangerous, it reminds me of an ogre smiling at someone (to make them calm down) who he's planning to eat a little later.