Sometimes a chump whose game was known by every NFL team after his rookie year (save Colon's beloved Packers)…is just a chump.
His QB rating was in the bottom 1/3-1/4 of starters in the league.
He grew up and went to school in 'very Caucasian' towns, most likely NEVER experienced an ounce of racist behavior towards him because he was a gifted athlete.
He had to blame his failure so early in his NFL career on something other than himself just not being that good.