I don't think they necessarily need to cash everything out in order to pay developers. If they have an account, they can just transfer the funds to their wallet. It doesn't even have to leave the platform unless the developer actually needs the money. So there's no reason for Steemit, Inc. to power down one of their large accounts and sell Steem on the external market just to make a payment to a developer, especially when they have available liquid Steem and Steem Dollars. That kind of defeats the entire purpose of the wallets and transfer functions, doesn't it?