Also, the general philosophy includes a preference for free market forces deciding the price of SBD.

This is a bogus argument, currently Steem has to bail out the SBD price every time it falls below 1$. And there's been many months where the price was staring to to nudge below 1$. The only reason why SBD enjoys high prices is because investors know that Steem holders have to bail out SBD if it falls below 1$.
A truly "free market" "with no rules" SBD would go to near 0 instantly without Steem backing it.
I would argue that allowing Steem to be converted to SBD is more freemarket than the current system preventing it. Steem investors are subsidizing this silly SBD coin which does not bring the benefits of a stable currency as envisioned in the white paper, and has held back the development of an online markeplace, not to mention the missed opportunity of taking away some of Tether's market share.