It was controversial because Messi would be the best in any team, not only here. And surely not because of his teammates.
But the quote that he made
did include the statement that he'd be "
obviously the best". The only way this ever became any controversial was because some newspaper only quoted that first bit without any context and left the rest out for clickbaits. I think it's quite questionable if the board of one of the
biggest clubs in the world - going by the slogan
Més que un club - acts against one of their own directors, because he was or was not slightly approving a stupid facebook meme, in an attempt to just give a little credit to the teammates around Messi that got shat on in the past few days whereas Messi himself was pictured as their imperial saviour.
A statement like this is plain normal and not controversial anywhere else but in Barcelona. And the reason for that is because they fear that it might fuel the argumentation of those they don't give a fuck about anyway. This is absolutely poor sport, not just the club gets bad PR, Messi does aswell although he might not actually have wanted that.