The age to vote used to be 21 just like drinking, but since they could be drafted, they insisted on getting the vote at 18.
Also, I think most people, even at the age of consent, are far too vulnerable emotionally to be having sex that is truly "consensual". I mean, just because your body is capable of reproducing you should have the right to go out and hump whatever? A rush of hormones is more involved than an actual decision making process.
It is far too easy to influence the younger guys and girls into sex already. There should be a reason we have it as a deterrent! How many young girls get pregnant in high school and can't go to college? It's hard enough to afford it and keep up with the course work as it is. Imagine if the school yard were opened up as the next frontier of sexual conquest.
I hardly think that the average teen is able to think about the long term consequences of things. How many people refuse to use condoms because they think their partner is a virgin? How many teens are aware they might have STD's? How many men feel that it is not their obligation to be involved in the baby's life, as they only wanted sex?
And yeah, pedophiles suck. I mean, I've seen some 13 year olds that look 18 when I was in middle school, so if it really was an accident I feel bad for those folks. Other than that, burn in a fire.
Just like an std, will never fully go away.