For adding POS mining we have to make hard fork, there is no other way. But we won't revert any block. Benefits for the devs? We're working on this project from 1 year and we didn't sold any single coin.
What do you think about using premined (genesis) coins in a POS systems, it is the same as cloud free mining, mining without having any cost?
It seems that you are replacing a problem with another problem, but you personally benefit from this.