Timstuff said:

Sith do love gray areas, though. Palpatine was able to lure Anakin to the dark side by first bringing him to a gray area of morality. Claiming that to understand the force you need to understand both the light and dark is about as gray as it gets. The Jedi way is "Light side = good, dark side = bad," whereas Sith claim that morality is relative and that it's up to the individual to determine what is right and wrong. The reason the line is so controversial is because it's the straight up opposite of how the Jedi and Sith actually are, and thus has no place in the story. If anything, it should have been Anakin telling Obi-Wan that "only Jedi deal in absolutes. I'm finally free of their single-minded dogma!"

Again, it's all a matter of perspective - I see Palpatine's words not as a reflection of his views or the Sith's of morality, but rather as a means of decieving Anakin into losing focus of what's right and wrong and luring him over to the Dark Side. It's also a matter of a person's perspective on the Jedi and Sith to the Star Wars series and whether or not those perspectives can be changed: in the original cuts, yes, the Jedi are dogmatic and controlling, but those aspects can also be changed, removed, and altered through editing (making the Jedi, the Separatists, etc., into far more ambiguous or "grayer" organizations)

But if you're going by the logic that you presented, then Anakin's line of "If you are not with me, then you are my enemy!" should also be removed as well, since that's the opposite of what you view the Sith as believing (since a Sith would not have "dualistic" thinking).