You would rather see McVay stick with a mistake to save face rather than make the right decision for the organization? Weird choice, but you do you.
If McVay hired the wrong guy, then fires him because he's the wrong guy, how is that scapegoating? Blaming the players, the assistant coaches, or the equipment manager could be scapegoating. Blaming the guy making the mistakes isn't. If the argument is that McVay hired the wrong guy so McVay is really the one to blame, what do you expect him to do? Fire himself?
McVay has a lot of things to answer for on the offensive side of the ball and for the team's mis-management of special teams. However, all of that is a separate issue from Morris not being the right guy for the defense. If Morris isn't the right guy, then Morris isn't the right guy. Who else is supposed to get replaced to fix the defense but Morris?