Why is our youth not voting?

I recall that during the last presidential campaign many influential and younger celebraties joined a cause titled "Vote-or-Die" and there point was to try to raise the percentage of eligiable voters from 18-24 to vote. Many celebraties from P-Diddy to Paris Hilton were involved in the campain cause and by the end of the election still less than half of our youth (18-24) was not voting and even Paris Hilton didn't "get around" to voting. Seeing how about half of our class can vote in the next election when talking to my friends on if they're going to vote or not most of them are either unsure or do not want to go through the miniscule task of registering and voting but then this raises an important question of if we the people of America have really the right to critisize George Bush or any other president when it is almost kind of our fault that we were the ones who put him in office or we were the ones who didnt vote.