The Morris D was not soft the Superbowl season, it was soft last year out of need and because it had to be. If the Rams can score points you'll see the Morris D be far more aggressive and in your face.
Rah didn't suddenly forget how to coach and McVay isn't telling him to get more aggressive, in fact, ill bet McVay was in alignment with the way the D was run last season due to the inept O.
The Rams D was stellar in that playoff and Superbowl winning run, I had no complaints, there are many reasons for what happened last season cause and effect. It's not just that Rah suddenly decided he preferred to go into a protective shell....the Rams had to do things that way out of necessity.