I think GMFP is hardly blind to what is going on. I also think he is weighing a number of factors which many have no concept of, as in, if he fires Anderson, what happens to him, his family (I know nothing of the man beyond football, so I stand to be corrected), his kids, etc.? He isn't just a drone that gets tossed to the side of the road and forgotten: he is a friend, colleague and member of the Frog Family of Coaches that makes such moves difficult.
I do not doubt that there will be some extremely hard choices to be made here in the next few weeks.
Somebody posted some old Bum Phillips quotes, and one of those (memory spotty) is apropos: "There's two kinds of coaches; them that's just been hired, and them that's about to be fired." It's a tough way to make a living, and those that read the SI piece on GMFP in the early days know that he led a life of a nomad. I believe he made a conscious decision to not play that game when he was named Head Coach, but sadly, sometimes such extremes are necessary. It is too easy for many Head Coaches to scapegoat their subordinates (ahem, Mack), but there are also times when the problem is such that the only solution is obvious. Ultimately, the duty falls to GMFP.
And he, of all people, knows this fact.