It is too early to consider SBD a fixed currency or try to make it a fixed currency. The quantity is just too small. This is the reason for it being unstable. It benefits the community for SBD to go up in value. This incentivizes Steemians to sell their SBD and promote the growth of the STEEM platform. Once the community has grown to a point that generates enough SBD to allow it to be a pegged dollar, then use SBD as a pegged dollar. Until then, there is no point to attempt to drive the price down by not making it exchangeable. It would be like getting paid in Hong Kong Dollar but at the same time arguing that Hong Kong Dollar is worth too much and should be less.