For the same reason that Keegan won't. They've both dealt with Ashley first hand, so they would know it's an impossible job. Still, reading those quotes, that definitely refers to Pardew being poor, even if he doesn't mention him by name. I think the absence of a reference to Ashley here is more telling than the absence of Pardew being named directly.
It's not an impossible job, though. He's expected to finish 17th and above every year.