Many fans don't care about stats. Just go on the Madrid forum and see what the fans there have to say about Ronaldo and how he's a cancer despite scoring so many goals
, or go on Redcafe and see how many United fans are seething at Rooney, who even though he has very impressive stats, they complained that he was always getting picked by Moyes despite his overall performances being poor.
Fans turning against their teams best player and wanting him to be sold is nothing new, it's happened throughout football history. If Messi does leave it would be sad, but just part of the football cycle, players come and go, don't grow too attached. I had to learn this the hard way when Ronnie left