They'll never do "proper raids" with Savage difficulty as that would mean having to do fights you've already beaten every time you want to prog.
People already complain a lot about having to do Kefka before being able to go into God Kefka, imagine if they also had to do Phantom Train, Chadarnook and Guardian.
And you can say that it's already how it works but at least with how it is now you can beat the early fights and then save the one you're progging on for the next day or something, so it's not as draining as doing them all in a row.