Steem is a very distinct blockchain where there are posts and votes. There is value therefore in providing a way to work with these kinds of transactions as you did with chainbb.

On the other hand, a crypto-currency must have some local way to send funds and use the owner and active keys. The idea of putting private keys into a website like we do makes my stomach turn. That is why Vessel is an important project. Of course being a witness should be your core concern. Are you going to keep maintaining Vessel?