They have a very clear aim. It is huge and urgent. And it seems their system and organisation is enough to realize it (though it is not decentralized).
Must to admit It is a fact. (though I still have some day-dreaming about Bitshares).
Centralization advantage is that it is "easier" at the moment since the world is set up for it. I know where to invest, who to hire, who is accountable, and who to fine.
Decentralization requires a lot more innovation, and is pretty much untapped, since you have to engineer in accountability (including regulatory accountability) and financial incentives which currently don't exist.
If I3 took over bitshares and "owned" it from the start, it might have been easier but with a lower ceiling.