That's right because Ronaldo never dictated the game when he played for Man Utd. Still think that part of the reason why Messi does so well is because he plays in a team built around him. Until he proves that he can play at the same level either for Argentina or for another club team, there will alway be that nagging doubt of how good he really is and rightfully so.
He hasn't dictated a game for nigh on 3 years, he's regressed completely in that sense.
Difference between Messi and Ronaldo is footballing brain, pure and simple.