The whole reason behind normal mode and savage is for the people who don't want to do actual raiding but still want to see the story. Locking a "true" ending. Behind savage would be frustrating for everyone involved.
Running savage content for weeks with no story reward (which is mostly what I play this game for) is frustrating for me. The most rewarding and satisfying thing in this game for me was seeing those story cutscenes in Coil after putting all the work in to clear it. Plus they eventually put in echo and gear carry so everyone who wants to clear it can.