Messi didn't act like this before it was absolutely necessary. Lucho has been here for half a season and has so far failed miserably and acting indredibly arrogant while doing so. He acts as if he doesn't have to answer for his decisions to anyone, as if his status as coach gives him absolute carte blanche until the end of the season, which apparently he thinks is the only appropriate time for any criticism.
You could argue that the players have even been patient with him. He got his chance, he got respected in the beginning like all new coaches does, in fact he got respected for a while longer than his actions called for, but nevertheless - once the "shine" of a new coach wore off, they quickly saw what kind of coach and person they were dealing with. Six months later and this happens. This is why a coach has to earn the respect of his players and gain their trust, if not he loses the squad. It's the same in every sporting institution with a coach figure.