Why would you choose Steem...
@meyemetheus has covered the Steemit FUD issue pretty well in my opinion, so allow me to offer another thought as to STEEM's preference over EOS for your project''s use.
The larger part of my cryptfolio is in Proof of Work coins, however the Delegated Proof of Stake experimentations fascinate me. STEEM is my one exception of having traded in DPOS coins when buying my Dolphin level.
The magic of DPOS governance allows STEEM to be one of the fastest and most scalable blockchain networks out there, yet it also holds a level of danger of corruption that one will not find on POW Networks.
In my opinion, and understanding, EOS has taken that potential corruption to a new level of fear by giving the governance the ability to change transactions on the blockchain if they meet a majority vote. EOS' Governance gives EOS Witnesses the ability to do, at any time, what Ethereum has done once in an action that brought about a hard fork (the real kind). There are some other checks and balances, yet the short answer is the EOS Blockchain can be changed after the fact.
For that reason if my choice was to use a DPOS Blockchain for my project, then STEEM would be my choice at this time. Although ripe for corruption in its own right, Witnesses cannot change past transactions.