As the population increases and school standards are kicked up a notch, the students of today are expected to perform at a higher level than that of their predecessors. Getting into their "dream" colleges, especially, has become more than just a competition of grades. Even kindergarten students are expected to know more than "A is for apple" and other basics.
So, are dropouts still dropping out because school has gotten harder? If we take out economic reasons, then one can argue that is so, and further the argument by stating that students who believe that they can't perform well also believe that they'll be better off without the stress. Yet, it is that lack of confidence followed by a lack of enthusiasm that causes more and more students to throw in the towel.
It is in human nature that we only do what has meaning to us -- whether it is just our reason to wake up every morning or to tackle our challenges head on. We should spread this source of enthusiasm. You never know whose life you could change.