Though I don't think the other thread was the place to debate it, I do agree with King that alerts going out one minute apart are completely excessive. It would make more sense to send it only once unless there is new information available.
The timing sounds like it was also pretty annoying. I'd be pretty irritated if I were woken up at 6am with an Amber Alert. Chances are, I wouldn't have seen the girl while lying in bed. Or at least, if I did, I'd have bigger issues on my hands than annoyance with my cell phone.