Really? The shallow propaganda of the 30s and 40s was somehow better than the stories of today? I don't buy it.
Seriously, humans are flawed. Humans are not always paragons of honor and justice. Today's superhero stories attempt to shed light on the fact, and set out to say that despite one's flaws, one can still help the world and accomplish great things. The early comics presented an extremely black and white view of good and evil: Superman is a blindingly pure Marty Stu whose morals are perfect, Lex Luthor is an unquestionably evil kitten-eating, baby-punching villain. Call me crazy, but some how I think the superheroes of today, with their baggage and shaky morals, present far better role models than the always-good, always-right heroes from the early days of comics.