My understanding is that SBD isn't really a stable coin. The peg is loose, so we saw it shoot well above $1 in a bull market and now its well below $1 in a bear market. I suppose the reason to hold it because if Steem goes back to all time highs, SBD.s are likely to do so too? Might not be a sensible plan in the short term but I think many people are just hodlers and are only interested in the long term.