Actually, the genjutsu moment is the biggest proof that he cares about her.
Let's see.
He openly declares to be HATED by everyone, including Kakashi (whom he does NOT plan on killing, no? he DOES plan on killing Naruto, so Naruto's opinion won't matter).
Now, IF he wanted Kakashi to HATE him the most - wouldn't it make MORE sense to KILL his student Sakura, instead of leaving her alive (and supposedly hating Sasuke as well)?
It certainly would.
Yet, he does NOT kill her - though he COULD and even SHOULD, according to his own plan.
No, he doesn't CARE about her AT ALL, ya know.
LOOOL!