Why do graff and Anderson decide not to interfere with the growing situation between Ender and bonzo?

Chapter Twelve's opening conversation is between Colonel Graff and a head of the I.F. military police, General Pace. Pace is worried about how Graff is dealing with the situation between Ender and some of his antagonists led by Bonzo Madrid. Ender cannot be hurt so badly that he cannot command. But Graff emphasizes that Ender can never believe that the teachers will help him out.