Simply put, why does everyone hate Meg? With most things in Family Guy, I'm expecting there to be some reference or joke being played out. Off the top of my head I can see if instead Chris were the one who was picked on, it wouldn't have the same comedic appeal and would instead just seem sad/cruel. Is that the only reason or is there a deeper explanation to it?
There is never any answer given in the show for this, but since Seth MacFarlaine seems to revel in deprecating humor, it's only natural that one character should be made an easy target.
Mila Kunis was quoted as saying;
"She's the scapegoat," Kunis described her cartoon character. "Meg gets picked on a lot. But it's funny. It's like the middle child. She is constantly in the state of being an awkward 14-year-old, when you're kind of going through puberty and what-not. She's just in perpetual mode of humiliation. And it's fun."