Thrawn. What was wrong with him? What mistakes did he make? Personal opinion...

I'm sure there are a lot of people who may not like this clip. But - I was interested in this character, I enjoyed reading the books about him, and I really disliked the ending. Just. such a stupid death. So - let's think about what could have gone differently with him?
So, first off - I realize that not all of my viewers are Expanded Universe fans like me, so not everyone may know about Thrawn. So who is he, and what is he even known for? So - I'll tell you now.