I blame the issues of people dealing with imperfection on television and glamour magazines.
this is actually very accurate. mostly these inadequacies have been instilled in women, about their body image, but that has a tremendous ripple effect into the rest of the culture as well.
a book that tears open this concept is The Beauty Myth by Naomi Wolf. i've never been able to walk past an issue of cosmo without wanting to burn it, ever since i read this book.