I have 5 resaons, all technical not taking into account the fundamentals.

1. They cant control what happens @ exchanges even if they peg it again on the steemit page. Doesn't mean speculators will stop paying a premium (anything >1$) for the potential to see another even bigger pump and dump on the exchanges in the future. If they bought @ 2,2$, the the associated risk is low, because it can't fall below 1$. There is no other asset with a fixed bottom.
2. SBD chart is bullish, BTC is starting to turn bullish too
3. I observed the prices of SBD and STEEM for months now. SBD is able to rise much faster, because of the lower supply. I believe exchange rates of 2:1 or 3:1 will easily be possible again. Combine that with the bullish chart and you get something like 6$ STEEM and 12$ SBD.
4. Mind game: Let's say you will be able to earn 30k SBD within the next 2 years. Why not put 6k away in case another pump and dump happens? It is a bet against short term gains and for longterm gains.
   Those 6k could be 7k STEEM now or 18k+ STEEM later this year or in 2019. If you are in it for the longterm I think this to be a decent bet.
5. Have a look at the most recent LTC/USD chart (for similarity) to get an idea what could be happening with the price of SBD in the next weeks...

If you don't have the nerves to follow through (I know it can be painful) then I would start selling above 1.2:1 ratio.