I don’t think Dan Larimer would want to negatively effect the Steemit/Bitshares communities so perhaps he would move in a different direction for dApp development. He has stated that he is creating EOS for himself to use and develop on though. I can only assume he has plans in the works after EOS is stable and running. The other thing to consider is it makes it easy for any developer to create a similar social network or trading platform on EOS so we should see competition arrise at some point.