He's just a popular man with the right friends and connections. There was a segment on him on sunday supplement and the first thing Shaun Custis said was something like "it's difficult, we were just talking about him and we all like him, but it just hasn't worked out for him".
As for Tim Sherwood, if Pardew was foreign he would be frothing at the amount of chances he's been given to fail over young British managers.