If you can think of another reason, I'd love to hear it. Not that you'll ever come up with one.
His best mate Jonas publically complained about Pardew's treatment of him when diagnosed with cancer and a week later Colo was in the paper defending Pardew's position as team manager. That's the type of person he is: he takes his money and does what he's told whether he thinks it's right or wrong. Leaders don't do that, but a captain who'd question those above is about as likely at NUFC as a manger who complains about players being sold.