Equity in the system is going to have high volatility regardless, because that's what equity does. As economic conditions change and more importantly sentiment about future economic conditions changes, equity values fluctuate a lot.

Ned Scott may have been right about SBD increasing the volatility of Steem (although, I personally don't recall him saying this and I'm also quite sure that it was widely understood so even if he did, it wouldn't have been any great insight), but he was completely wrong about trying to combine a utility token with a currency.