The fact that you don't think a movie(especially a trilogy) would need character development means you aren't qualified to have this conversation because you obviously don't understand how a story works. Enjoy the rest of your day.
I never said a movie doesnt need character development. What i said was if its not one of the main character there is no need for them to waste there time getting into the mind of Count Dooku when there are other storylines to concentrate on. Like i said earlier if you need to know the back stories on these characters then you should read the books or hit up a wiki.
There is a Clone Wars cartoon if thats what suits you.....Im sure it will give you plenty of insight on Dooku's thinking