In my humble opinion, BTS is so much more than Smart Coins at this point in time. We shouldn't let that one feature shape our whole worldview.
Whether it's more liquid Smartcoins or an even more awesome, popular sellable product/UIA, the ability to transfer them privately will surely increase potential demand for them and as a result increase the value of BTS shares.
However without sellable product, stealth transfers won't necessarily increase the value of BTS unless the belief is that BTS is currently undervalued because potential shareholders are reluctant to buy this amazingly undervalued company without privacy.
So I would think focusing on SmartCoin or other 'better than Smartcoin' product would ideally precede Stealth, not critical though.
Although I am sympathetic to this position, I do believe that privacy is a fundamentally important feature. That implementing it should have already been well underway is irrelevant here.
The same argument could have been made for 100K TPS, and in fact CNX finally did realize a slower TPS, far less than 100K TPS, is perfectly acceptable and yet exceeds BitShares 1.0 performance by a large margin, thus a significant improvement.
The point is it was an investment in infrastructure anticipating future adoption of BitShares. Who would have signed up for 100K TPS back in the 1.0 era over wallet improvements and stability? I know I wouldn't have, yet BM saw the value in a new architecture that not only provides 100K+ TPS but so many more benefits as well.
It's not difficult to see how much of a barrier it is to those with lots of wealth to go public and place a significant portion of that wealth on the BitShares blockchain for all to see, scrutinize, target and try to get a chunk of. I know the concept of privacy it counter to the mainstream norm these days, even in this community, but it is a very important foundational principle to this ecosystem and to preserve and strengthen freedom.
I'll admit I don't know what the best approach is to prioritize improvements and implement new features to give BitShares the most optimal chance for growth and adoption. I can get so focused on a narrow view of things at times and in that tunnel vision choices seem easier. And of course trade-offs are always easier in retrospect. What's obvious to Stan & Dan may not be obvious to many of us. Historical judgements and choices made here fuel my skepticism and cloud my perspective of the future.
However, I gotta say the approach described by the OP is one I believe will help qualify what to focus on based on the hard empirical evidence of what people are willing to pay for. I like this very much. But I am still concerned we're trying to sprint to the finish line and overlooking other important, less exciting factors that directly impact adoption, especially by developers, such as quality, detailed documentation, tutorials and API "how to" examples. I did like what BM said here:
The assumption for all features is that a working reference GUI will be provided to make the features accessible. Each feature will be fully documented with a detailed design complete with UI wireframes prior to Cryptonomex taking any money. We want to ensure that the community knows what they are bidding on and to maximize the price we can get for each feature. Bidding can start early (prior to detailed documentation), and users can cancel their bids if they change their minds prior to us locking them in.
The context sounds like he feels there's more of an incentive to be more thorough and rigorous regarding docs and UI / UX prototyping b/c it is tied to maximizing the profit from his work. It improves quality, and quality sells better. I think he is right on the money.