the opportunity is not ever "wasted", as put earlier. There are always plenty of opportunities to take tests for aptitude in many ways, SAT, ACT, state testing, etc. Heck if you want lots of testing there is always the option to help a kid "find him/herself" other ways and with other tests---- you can always consult a good child psychologist or developmental specialist; they have plenty of these tests without obligation and are better-written and not as limiting as ASVABS, anyhow. The ASVABS serve to alert the military as to what capacity your child would be best used by the military, not the other way around!
The ASVABS will ALWAYS be there for them at the recruiter's offices, where I believe they belong, not in the schools.
I am no anti-war activist saying this, but a military veteran of 10 years' service---who would, on one hand, love to see my son follow Dad's and my footsteps and serve in the USAF. Like I said, I know plenty will disagree and that is fine. But my son won't be taking ASVABS til over 18 and on and of his own accord, not the schools', the recruiters', or even mine.