Well, I found the answer; I don't know if she's right or wrong;
  but Carol Dweck's "Mindset" idea seems to be the driving force
  behind this.* She is an academic researcher - and her notion is
  that "grit and tenacity" are better indicators of success; and
  she has the idea that we have to move away from a mindset of "I
  have talent" to "I don't have talent, but I can grow if I work
  hard." So - these ways of teaching and testing are designed to
  promote failure;* fail, rebuild, fail, rebuild, fail, rebuild,
  fail, rebuild, until at the end - theoretically - you end up
  with a student who believes that hard work is more important
  than talent. SEEMS good; and I really really really hope the
  research on this is STRONG because: this method (very similar to
  the method that the Military uses to break down and rebuild
  Soldiers) - discourages those who seem to have an aptitude, say,
  for mathematics; and keeps them from trusting in their own
  abilities; encourages them to expect failure, but then feel they
  have the ability, through hard work, to "make it". I sure hope
  she's right; it's an experiment that's being performed on
  millions of kids right now; and a WHOLE LOT MORE next year. I
  just worry about nervous breakdowns; I know people who went
  through bootcamp in the army and were sent out because the
  "break down/ rebuild" really cracked them... badly.* I have a
  fear that the ones who have an apititude for math will not only
  lose their confidence (which the stepwise program is DESIGNED to
  do) - but will never fully recover from it. I hope it works; now
  that I see the way of thinking behind it.. I'm a little nervous.