No, actually it does. That's what makes it Star Wars, and the world of Star Wars was carefully constructed to allow it to be so. One may more strongly believe in the Lawful rather than the Evil part of the Empire's Lawful Evil, but you must accept both on some level.
Attempts to force grey morality through Star Wars fail as stories about that universe almost without exception.
Erm... you don't even have to look outside the original trilogy to see Yoda is wrong.
Yoda's point of view is that you are either on the light side or on the dark side. Once you have fallen, you can NEVER EVER come back.
And yet, look at Darth Vader....
Then there would be Lando Calrissian and Han Solo. Both of them apprenetly good people, and yet they both steal and betray. Now one can argue that they only do that to the bad guys, but does that make a crime just, if you do it to a criminal?
If we include the new trilogy, we can see Anikan killing women and children of the sandpeople, while still staying on the light side for quite some time, clearly hovering between the two exremes, something that would be impossible if it really was only pure black and while.
Then there would be Amidala pretty much kicking the old chancellor from office to save her world, risking to make the situation worse for the whole republic. This could be naivety and ignorance of the enormous impact of her actions, but for me it looks more like she puts the live of her people before the rest of the galaxy. Again something an unblemished, pure light sider shouldn't do.
