Norris got caught between sizes. He didn't feel he was big enough to fight as a HW, though he probably could have done well there. He just wasn't a big puncher at that weight. Then he went down to cruiser and, in my opinion, lost to Arthur Williams and Adolpho Washington (who boxed a beautiful fight that night), and he wasn't a big puncher there, either.
He just wasn't meant to knock guys out and he should have stayed at the higher weight, probably made more money.