Messi is a far better team player - relies far more on skill than on pure pace and strength to evade tacklers, and seems to me (I don't know assist counts) as a far more willing passer of the ball than Ronaldo. Against Holland, Ronaldo complained quite a few times for not getting passes when he was in better positions than teammates and than when the roles were reversed, refused to pass. He's a vain cunt, who's got Messi on his mind non-stop (his comments earlier). Messi isn't 'light years' ahead of him, but he's ahead of him and if Ronaldo wasn't so busy changing hair cuts at half time, or taunting his own fans, he'd probably admit it himself too. He's a cunt, albeit a world class cunt.
I'm not saying there isn't something in what you say. But that's a function more of (a) them being different kinds of players; and (b) Messi being brought up through a uniform football philosophy since he was a nipper, rather than one being naturally a superior player to the other. Consider also that Ronaldo has been successful in two vastly different leagues, playing for managers with different playing styles. That also requires an ability and skillset that is very rare, and that is something that Messi has never been tested with. You can also of course argue that Ronaldo's ability as a team-player has never been tested in a possession-based team set-up like Barcelona, but I would be tempted to say that Ronaldo's chances of success in such a set-up would be greater than Messi's if he ever moved to the PL, for instance. That's of course hypothetical, but given that a comparison between two players (given that they can never be identically placed) requires some degree of hypothesis, I think that's only fair.
I also think it's interesting to compare their stats:
Messi (Barcelona)
2004-05 – Goals – 1; Assists – 0
2005-06 – Goals – 7; Assists – 1
2006-07 – Goals – 17; Assists – 2
2007-08 – Goals – 18; Assists – 13
2008-09 – Goals – 38; Assists – 16
2009-10 – Goals – 45; Assists – 10
2010-11 – Goals – 50; Assists – 21
2011-12 – Goals – 73; Assists – 23
Total – Goals – 249; Assists - 86
Ronaldo (United and Real)
2003-04 – Goals – 4; Assists – 4
2004-05– Goals – 9; Assists – 6
2005-06 – Goals – 12; Assists – 7
2006-07 – Goals – 23; Assists – 20
2007-08 – Goals – 43; Assists – 8
2008-09 – Goals – 25; Assists – 8
2009-10 – Goals – 33; Assists – 7
2010-11 – Goals – 53; Assists – 14
2011-12 – Goals – 64; Assists – 15
Total – Goals – 266; Assists – 89
Ronaldo being older has played an extra season and consequently has slightly better aggregate stats, but I'd say they're absolutely neck and neck on average. Messi's obviously won more at club level (5 league titles, and 3 CLs) compared to Ronaldo's 4 league titles and 1 CL, but again that's more down to the teams they play for rather than any individual superiority IMO. It would be interesting to do this comparison at the end of their careers, but my thinking is they'd be absolutely neck and neck. Messi will always have more fans - not only is he far more humble and understated, but he is also a purists' delight, unlike Ronaldo, who is cocky and smug, and is seen to be be good because of the fantastic physical gifts he's blessed with. For those reasons alone, Ronaldo can't win, but any objective analysis must place them at a hair's breath away from each other, and not Ronaldo at a distant second, as so many often make it out to be.