What I say is: Thanks to the speculators for the higher payouts to the authors. :-) In my opinion people speculate on SBD because of its low marketcap and people don't really know what SBD is. People have also take into account that inflation of SBD rises with its price. And inflation then causes downward pressure.
Here I have a chart where you see the price of SBD versus the inflation:
Its from my weekly steem statistics. https://steemit.com/steem/@sevenseals/steem-statistic-charts-week-03
Yeah I think many simply do not know what SBD is - they are not aware of it to be a stabilising "currency" for Steem - but if they are no Steemit user I can understand that.