I don't think there is anything wrong with SBD. Given the ratios rewarded in the 50/50 split, this is a self correcting problem. It may take a while but it will correct itself. In any investment when the number of investors are relatively limited (like with steem/sbd) there will be volatility. It's unavoidable but will also be self correcting if and when the community is large enough. There is already a market for buying and selling sbd built right into steemit.

It isn't clear to my why SBD rose so much in value but I suspect it happened in large part due to the fact that it was generally encouraged that people power up 100% instead of taking the 50/50 split. Maybe then the "fix" is simply to not even allow this as an option? If users want steem for their SBD then they have to use the currency market to convert it. More SBD means a lower price for each SBD after all...