I don't think Lena Dunham put fingers to keys consciously saying "people will TALK ABOUT IT," but she's part of an era* that is hyper self-aware, oversharing and implicitly vain (that's not to say that there aren't young people who do good things- but a) and b) make them SEEM vain about their involvement). So her writing's going to come from that perspective.

*I was going to say generation here, and then I realized that there's a ton of self-centered media and political discourse coming from the two precedent generations right now(see any Tea Partier complaining about why their taxes are paying for "x program" and 30 Rock, which did reactive writing long before Girls hit the screen)