One of the reasons dropout is high could be the low quality of education one gets at school. To get an idea of how low the quality can be, just watch this documentary from ABC:
To be fair, the quality of education could be a reason why one is tempted to drop-out of school. But, even if you got "good" education, I suspect that you could get an even better one designing your own curriculum and studying online.
And to be fair again, my guess is that the average quality of education is going down everywhere in the west, while going up in the developing countries. The difference from the past is that one can compare what is being taught at school with the "knowledge" one can get online (if one can filter, of course).
Kids today are learning the basics at school, but the motivated kids can get high level knowledge online if they want. Just think about how many kids participate to Open Source projects.