I'm going to start out saying I'm only 19 and never saw much physical bullying, but I think the question is based on flawed logic (namely that nerds are bullied for liking nerdy things)
I'm a huge nerd, I was in three different school trivia clubs, liked most of the teachers, 4.0 average (actually a bit higher because of AP classes being weighted funny), wore geeky shirts, big glasses, and had bad allergies. But I was never really bullied. I'm the kind of kid who doesn't fight back no matter what. I won't exactly take a beating, I'll talk to them, tell them to stop, and I'm good at making people feel guilty, but I'm a pacifist so fighting back is out of the question.
That said, I was also the kind of kid who loved science and knowledge so much that I would help kids with homework and tutor them when they struggled just because I liked having the ability to share knowledge. As a result, I was friends with a lot of the popular girls and the athletic crowd. Somebody said something fairly mean to me once, can't even recall what it was, and almost immediately got punched in the face by one of the football players whom I tutored in math. I didn't even want the kid to get punched, but I suppose I accidentally built myself an anti-bully armor.
I never really witnessed bullying, certainly no physical bullying, but I did see some people who thought they were being verbally bullied that I don't think were. I had 2 friends, L and A. L was a nerdy girl on one of the trivia teams I was on, A was a popular girl who wasn't very great in school but tried really hard and was very nice to most people. L once told me that A bullied her. I was shocked because it was out of character for her. Next semester, I had a class with the two of them and L would laugh and joke whenever A missed a question. After class L tried to talk to A and A just walked away. L viewed this as A ostracizing her for being smart, not for being a ***** to A. Another friend (though friend is the wrong term, more a friend of all my other friends) named K would constantly make fun of and sexually harass the girls, and couldn't grasp why he was single or disliked by them and seemed to think all the girls had it in for him. Nearly every friend who I had that claimed to be bullied this was the case. They'd do something rude, weird, or nasty to someone else without realizing it and then would see any response as bullying. I can't guarantee that this is always the case, but in my school the victims were almost always the ones who fired the first shot without realizing it. This isn't true for everyone (one kid had serious mental and emotional problems and would punch anyone who walked too close to him) or even for everywhere I imagine, but it certainly was for my school, which, by the way, made national news for being filled with bullying. Mentor High if anyone is curious.
That said, the machinations in play in my school district to allow bullying to continue, in fact to thrive, were ridiculous. You would think it was designed to keep the kids fighting. In my Elementary School, a girl told a teacher that some of the kids were refusing to let a different kid play basketball with them. The girl who reported this was taken to the front of the class, given a costume tail, "The Tattle Tail," and the entire class was told what she did. The fact that the teacher had the costume tail laying around makes me think this was a common occurrence, and the fact that the teachers singled out people who reported bullying to the bullies is horrible. I didn't know anyone involved in the incident (it was a big school) so I don't know what happened.
EDIT: A few exceptions to what I stated: race can single people out without any fault of their own, and parents abusing children, the child is never at fault in my eyes.