I think it is his right to step down/back or whatever he has in mind with this move. As I am creating a Steem SMT myself right now with the purpose of maximizing decentralization and distribution, I aim to step back eventually as well. Right now I need to push the whole thing but I really hope that others will step up and take responsibilities to develop 1UP further. Maybe he has already ideas for the next thing, like Dan Larimer after he created Steem and was already thinking about EOS.