Responsibility to the community. It's by community consensus that power is granted, responsibility should come along with it. Steem is a project in collective governance, it's not just a social networking site. For it to work that has to be recognized, even if the goal was simply to be a social network that pays.

I can't find a moral flaw in selling, renting and leasing an asset to someone else.

If it undermines the system as a whole, which is owned by not just you but every other stakeholder, that is a moral flaw.