I think some people just don't like him, it personal. he's a first team player, by that I mean a guy you want on your bench at the very least.
He's quick, agile, reads the game well, has a great understanding with his peers, Rash, Pog, Martial, has a belter of a right foot and probably has the best movement in and around the box in the team (sans Mata), on top of all of that he has been at the club since he was in nappies through to the academy (which you would think would buy him benefit of the doubt since academy lads are fetish in these parts, but no).
Some people just don't like him on a personal level, most likely down to his social media antics.