People love to @#$%& on Fisher these days, but I don't think he deserves all of it. His main fault was not bringing in a top OC to fix the offense, but Schottenheimer was pretty well respected in 2012. Very few fans were really unhappy with that hiring at the time.
Trying to replace Schotty in 2015 was a lot harder than people realize (and it's still not clear whether he was fired or he quit). The Rams didn't have a QB, and Fisher had 3 straight losing seasons. No respectable OC was going to join that mess - head coaches typically don't get a 4th and 5th year when they're below .500. So that's how we ended up with Cignetti and Boras - 2 guys who never could have landed an OC job anywhere in the league.
I think you can lay some of the above blame on Kroenke - keeping Fisher as a lame duck HC was a mistake, but Kroenke needed him to see the team through the move to LA. If Fisher was fired after 2014, no one would have batted an eye, and maybe Fisher gets another shot at HC somewhere.
Judging McVay right now is like trying to grade a draft after one year. His offense has been better than expected so far, but his real test will be whether he can keep all 3 phases humming over the next couple years.