SBD was never designed to be a free-market crypto. In fact, it's production schedule is based on the USD price of Steem. SBD production is already dependent on fiat and tied to it. We already have Steem as a free-market crypto. So, it's not a true "free-market crypto."

Second, a peg would not be manipulating the market. We would open up conversions from Steem to SBD which would introduce more SBD into the market so the artificial scarcity that is pumping the price would be relieved.