What happens when Steem has a huge fallback?

I suppose that all SBD is guaranteed to be paid out at near 1$.

The value of STEEM and SP will go down, maybe to zero, but the amount of STEEM and SP stays the same.

SP will still gain interest and blogging is still valuable in SP and SBD.
I suppose that the rewards in SBD will not be the same at that moment (in the dip), because the total STEEM and SP have not much value.

And after the dip/crisis, the STEEM and SP will regain value as long as the Steem blockchain/community will convince people that this is the way to go mainstream.

Where is the risk or is this indeed a wonderful experiment, almost like heaven?

Is this correct or can someone explain this more in detail?