I will have to agree with suu_no_clover; this, to me, doesn't seem like an AU Sakura - it rather looks like the polar opposite of everything that Sakura is. The very point of fanfiction is, to me, to portray the characters accurately and, in the case of AUs, making their personalities different but still keeping true to their 'soul', in lack of a better word.
Sure, you may have good reasons as to why your cast behaves as they do that eventually will be revealed (although I have a hard time seeing Sakura being like that no matter what she's been through), and it's understandable that you feel frustrated when people don't take the time to read through it all, but you know, that is how it works. No one will bother to read a story just because the author promises it will eventually pick up and that answers will be provided in due time - it has to be good from the very beginning.
In other words, I think you've started in the wrong end; it would have been better to start off with a Sakura not too different from the one we know, and then gradually let her evolve into 'your' Sakura, allowing the readers to see what causes her to become like this. As it is now, people will take one look at it and assume that you don't know CCS. I hate to be harsh, but I have to be honest.
On that note, try not to disregard people's opinions on your writing even if you don't agree with their standpoint - in fact, it is the ones who dislike what you do that you should listen to extra carefully, even if their words may not exactly be pleasant to hear.
