In a somewhat stable or growing market SBD works "fine". Historically it hovers around 40% within 5 cents of one USD and about 60% of the time within 15 cents. I deleted the file where I did that study so I might be off a little bit but it's within that ballpark.

The problem is that the crypto market has huge swings and the mechanism that makes the corrections to the supply takes to long and therfore the market can't correct itself fast enough. I think that the changes made on HF20 have proven to be counter productive. It only lead to an increase in the printing of SBD and a substantial increase in the real inflation of steem way above the schedule.

Now with the SPS printing SBD without regard to the 10% rule it just makes it not worth it.