From a content creator perspective sbd Goins down to $1 or lower will be a bad thing from a purely monetary sense.
If we really think about it though, the fact that sbd cannot be maintained at $1 is a bit of an issue because it loses its value as a currency that's relatable to something we know how to use in real life.
So what if sbd drops below $1? Maybe the Steemit Dev team might finnaly have a good excuse to kill it off completely. Sbds are sort of useless in every other sense.
Could sbd really drop below? Well sure, but you would earn an interest on it so people buy it as a means of earning free returns as you said. Do you know if there is a cap on sbd interest below$1?
Hm, SBD is really useful when pegged to the $ - so I don't see a reason to kill-it-off.
APR in savings could be really interesting.
The issue is that it can't stay at $1 and if trends hold true sbd will always go in a boom bust cycle due to the nature of how its created.