The reason: he was receiving too many abusive and insulting messages.
The culprits: MANCHESTER UNITED'S OWN FANS!
After receiving a slew of messages telling him that he didn't deserve to be on ManU and that he had no skills, Gibson stood up like a man and...deleted his account 97 minutes later.
It's nice when the fans of the league-leading team have time out of their days to berate one of the people they are supposed to be cheering for. Job well done fans. Job well done Gibson.