Ah, now see. You have a higher opinion of Snape than I do. I took it as they started out teasing, but he lost the thread and out came the bitter little tirade about hypocritical Gryffindors. ;-)
You really hate her. You don't even know where the story will go and just assume that she'll never learn. We probably have different ideas of what she needs to learn
NO, I don't really hate her. I just am frustrated that she's not showing an ability to think things through by now. We may have different ideas of what she needs to learn, I'm not sure. Because in my book, there's two primary areas in which she needs to learn. The first is to think through and anticipate all the outcomes of her actions (which is what I mean when I talk about accepting responsibility). So, for example, she should have thought through the logical and obviouly forseeable consequences of using such a nasty hex on the DA members without warning them. And, having forseen the obvious consequences, she should have thought a little more about it and come up with something else.
The second thing she needs to learn is ethics. It appeared she was fairly well grounded in basic morality BEFORE getting to Hogwarts. Unfortunately, McG and Dumbles did a good job of warping that. But part of the problem there is that she has not yet learned to think things through. And without learning to consider the ramifications of your actions, a person is not really in a position to talk about ethics OR morality (let alone lecture anyone else).
And I do not think Snape is trying to teach her morality. I'm not even sure he's in a position to teach her either morality or ethics, although perhaps ethics. But that's not what The Art of War is for. It's to teach a person tactics and strategy, in other words all about my first thing she needs to learn.
They were told by Dumbledore to never tell anyone about them.
But those three live to break the rules, especially when Granger thinks it might be necessary or advisable. She in particular has always been clear that rules are wonderful things, when applied to everyone else. ;-)