I don't know what else Messi should have done in this season. Okay should have scored a penalty.Your examples are interesting because both those players won the award for contributing greatly to their team winning a major honour, something that Messi has not done this year. Messi though still managed to win the Ballon D'Or in 2010 even though Iniesta, Xavi and Sneijder had better seasons in terms of silverware.
I have a feeling that even if Ronaldo leads Portugal to Euro glory, which is a really big ask considering how the Portuguese squad measures up against Spain and Germany, Messi will still win the Ballon D'Or
Messi is the most talented player in the world, without question, but such is the admiration for him from his fellow professionals and the media, it is going to take a whole lot (and then some) to take that award from him when he is scoring 70 goals in a season.
I feel that Ronaldo will have to put in two crucial and brilliant performances in the semi final and final to even stand a chance.
He did his bit, come on.
More than what he did last year.
Regarding Ronaldo winning Ballon D'or, not Messi's fault he doesn't have an international tournament to play in; and Ronaldo will win it if Portugal wins the Euros.