what should keep SBD equal to 1 USD? I understand that if everyone thinks it's worth 1 USD that's what it is worth but how can that be controlled or how can the people behind steemit do something that brings SBD value back towards 1 USD.

Most steem I assume is locked up as Steem power, and people can earn ( mostly SBD) by keeping Steem power and voting, SBD has an advantage that if you need the money you can sell it quickly