Besides the reasons I listed above about Kristen and the kids, I think we have to remember that she's not the star here. She's at the shows to support her husband and his friends. She didn't ask for the attention. We aren't HER fans. I'm sure she's not being blatantly rude (and yes, I've heard all the stories that she is and isn't rude), but she probably just doesn't want to be bothered. I know when I don't want to be bothered, I'll pretend I didn't see people that I know when I'm at the grocery store, the bank, the gym, etc. It's her right to acknowledge people or not.
EDIT--Regina, you must have posted right before me! You said it very well!
