Emotions are bad when they jeopardize the safety of yourself or others around you. She is a burden she went to attack sasuke from behind( in the middle of battle with kakashi) and guess what she didn't kill him she instead cried he then grabbed her and made an attempt to rid the narutoverse of her existence. She disobeyed an order from her superior (kakashi) and then kakashi was then forced to run to try to aid her because she failed to not only listen to orders but to execute her actions because of her emotions. This is an example of why not only your emotions can be dangerous but how Sakura is a burden.
Yes, she cried. Why? Because she realized that she cannot kill Sasuke, one of her former team-mates.
Something that has happened with others only she gets the hate.
Sakura in the first place didn't even called Kakashi, he was the one that followed her. True that he said to go and heal Karin first and then went back, but why? Because she didn't want to let Kakashi weight the whole thing alone, that was the hidden message behind her actions.
Of course she didn't kill Sasuke, if she had done that, it would be out of her character to do it.
If she didn't killed him, she gets the bashing, if she had killed him she would still get the bashing.
However, it was plain normal from the very first beginning that Sasuke wasn't going to get killed by Sakura.
The whole scene served as a plot device for Team 7's reunion and especially Naruto and Sasuke's reunion.
The thing behind was to show once again that she is that type of shinobi who wants the world to think and act differently, not to be mere killing machines, not to be merciless ninja tools like the previous generation was.
And, yes, it was a plot where it showed that emotions are bigger than any killing intent you have. This is not the first time when we see that. Sakura gets emotional when only people close to her are involved.
She is not the first that has done this.
We have Hiruzen who couldn't bring himself to kill Orochimaru in the beginning because of his emotions.
We have Tsunade that was about to betray Konoha because she wanted to see once more her brother and her lover.
And we have also many other examples that emotions change the course of a battle. Hell, the biggest threat of one of the most powerful techniques nowadays is emotion (EDO tensei) and people only bash Sakura that she lets herself run by emotions when people dear to her are involved though we have other examples?
We've seen that when it comes to protecting those two, no matter what, no matter how weak or powerful or however she is, she gives her best. But of course, those parts are forgotten because of that one time she couldn't kill Sasuke.
