I can't quite see Lois, Brian, Stewie or Chris saying "this is going to ruin my social life!"
Yes, all the characters are snarky and selfish to some degree, its the fun of the show, but their archetypes are clear and Meg is essentially the hidden truth about teens - they protest, they moan and ultimately feel life revolves around their own dark cloud, and what's worse, most who cry foul at those who make them feel crap would do precisely the same in their position - if they had the confidence/looks/whatever.
Family Guy is one of the few shows which manages to expose the teen truth, and its one we've
all lived, or are living. Teens are annoying, hypocritical, arrogant and self centered. Meg is the epitome of this, and I love the way that if she got the power that has controlled her, she wouldn't have learned from her ordeal, she'd just do the same to others. As most teens world - hell, as most adults would.
Meg is a fantastic little bit of social observation and I love the way the family treat her as the obnoxious character she is, rather than pandering to the woes of her superficial life as so many other TV shows do.