Putting a condom on isn't that hard, nor does it take a lot of thought. Less so for the pill. That's a dumb argument.
Plus, unprotected sex is obviously on the rise - when information has never been more available. What's the theory then? Teenagers are getting dumber?
Emphasis being placed on abstinence only sex ed, I'd imagine. If I was a teenager and I had the opportunity to make fuck, I doubt I'd research safe sex. Why research safe sex when you can be doing something more productive, like beating off?
And without being able to back this statement up, I think that even if they do know the risks, the "it can't happen to me" effect is in play. Teenagers are too young and inexperienced in life to know that yes, bad things can and will happen to you.
In other words, kids should just be sapped in the back of the head and kept locked in the basement when they are between the ages of about 12 and 25.