Like I said: bitshares bitUSD.
As it stands now, everyone with Steem is paying the interest for everyone with SBD, and SBD is selling off steem every time the Steem price goes up. It literally cannot go up. Without the potential for upside, nobody wants Steem, they then buy SBD, and the problem goes around in a circle, and none of that SBD is convertible. You can burn it at @null, or you can sell it to someone else. But it's going to sell steem to keep the steem price down against the dollar. That should cost SBD holders, not profit them.
Also, nobody is going to bail in your Steem (or SBD, or SP). If steem doesn't appreciate in value that's because most people are abandoning it. So it is supposed to be an indicator to tell you what you should do with it. Value keeps dropping, ditch it before you lose even more money.
With no witnesses to run the network with Steem under 5 cents, it's a moot point how valuable your SBD is. Nobody is going to be able to trade it.