You are wrong bro, in the forerunner/flood war, the ancient humans were neutral with the foerunners, they found a cure and soon enough were attacked by the flood. So the ancient humans landed onto forerunner home planets and was seen as attacking, so the forerunners de-evolved the humans, but survivors destroyed the cure in a revenge. But at the final stages of the flood war, the forerunners chose the humans to be the care takers of the galaxy once the left. So in their minds (and the precursors) we are the reclaimers.