I don't think it's fair to conflate the instability in the AD's office to the position of head football coach. Yes, it can be worded in such a way that Rutgers has had three football coaches since 2011, but also so that it has had three football coaches since 2000. One guy was there for 11 years, one guy for four, and now the third is early in his tenure. That's actually as stable as many (more than most?) programs. Yes, the AD office has been a ridiculous turnstyle, all due to bad hires exacerbated by difficult circumstances.
But to Ash being on the hot seat or not: It's way too early to put him there. He's in year two, and he took over a program that was basically broken. Flood did a lot of damage, and it takes time for a football program to recover, especially when it has just moved up in class against opponents that are so well-funded and enjoy traditions of success. That's not to say it's clear he's the right guy, but it's not at all clear to an interested but outside observer that he is not the right guy. It's just way too early to say. He's in the classic race to recruit enough talent to start winning before he loses too much to recruit the requisite talent.