SBD's are designed to not have a fixed supply (even now). They are being printed like fiat money (except slower and less efficiently). The issue is that there is so few of them that when a speculative wave comes they jump up in price and people think they are worth holding. Over time, SBD will return to the peg. Either that or Steem will not increase in price.

There is no manipulation in a peg. It is a market instrument backed by Steem but people are using improperly and reducing it to a speculative token.