Orochimaru says, "You want power and I have that. If you want, you can have it too. You'll just have to pay the price. Give me your body."
Akatsuki says, "You want peace and so do we. If you want, you can help us get it. You'll just have to pay the price. Give us the demon."
Sakura thinks, "I want to prove myself and become a different person. If I become Hokage, I can do that. I'll just have to pay the price. Hah, paperwork!"
Sasuke gets his power and goes mad with dreams of vengeance. Naruto yearns for peace and goes mad with every life he takes. Sakura becomes Hokage and never sees herself in quite the same way after she kills both of her former teammates.
(Somewhere, in the corners where dark secrets hide, is the desire to destroy the ones that forced her lost little boys to insanity. Somewhere, in the basement where dumb ideas go, is the thought that maybe she could fix the world and make sure that little boys and girls do not get lost anymore.)
She contents herself to signing paperwork.