I agree with you on the point that Justin might be a positive factor for the STEEM price, but if you're going to trade a stable price for a decentralized blockchain then there's no point to have a blockchain at all. Just let Justin compete with Zuckerberg then and have him create a new type of Facebookish social network...
I deeply respect your opinion, but you have to factorize that the target audience for a blockchain-based social media is one that likes decentralisation, and that it's an audience that is willing to bear decentralization's strengths and weaknesses