As long as you have the SD it will prevent the Steem market from maturing.
That really really doesn't make sense. There are plenty of price-stable places to put your money if you want a volatility hedge; for example: USD. By your argument, "as long as we have the US Dollar, it will prevent Steem from maturing." I have a (relatively) large SBD balance; I have that balance because I want price stability. If I were forced to get rid of my SBD, I'd simply convert it to USD.
Maybe but my view is that it distracts attention from Steem itself. Right now you have two choices if you want to invest in Steem, Steem itself and SD.
I would be interested in some professional economic opinions on it.
That doesn't mean everybody would. It is not a straightforward issue and I think everyone does things differently. That is why how markets behave can often be counter-intuitive. For everyone who sells there is also someone who buys.
I'm certainly no expert though so I would love to get some feedback from someone who has professional knowledge in this area. Perhaps there are historical examples of something similar that we can use to guide us?
Also what do you think of @tombstones suggestion of reducing the interest on SD?