I think this point is lost on too many people. Bitcoin doesn't really act as a currency. From what I have observed, at least since 2010, is that Bitcoin "users" don't actually use it - as you said. It's not a transactional currency. And it is quite volatile, despite its current price, market cap, and trading volumes. This has always been the large barrier to widespread adoption for merchants.
SBDs actually resolve this issue and can change the nature of crypto adoption for merchants. With SBDs, they don't have to instantly cash out in order to protect themselves from volatility. The SBDs can be held, remain in the STEEM ecosystem, and then be cashed out only when needed to realize profits in native currencies. As long as the peg can hold, there's no immediate need to ditch the currency - and this actually serves as support for STEEM holders by stabilizing the currency and the network altogether.
This notion that SBDs are only harmful to STEEM is absolutely absurd. There is no eternal "downward pressure" on the STEEM price simply because of the existence of SBDs. The pressures on the STEEM price are multifaceted and mostly have to do with factors that are wholly irrelevant to SBDs. The largest downward pressure on the STEEM price is the huge lack of interest in the currency and the Steemit platform. SBDs are an afterthought in that regard.