The evidence suggests that yes, they are as dumb as rocks. You're talking about what should happen. I'm talking about what does happen.
Or perhaps it would be more accurate to blame peer pressure or some girls' emotional neediness. Regardless of the cause, some teens will get pregnant because parents are not able or willing to prevent all pregnancies. If a program such as this can reduce pregnancies and the associated abortions, why not fund it? Society benefits in the long run, both financially and socially.