I'll preface by saying that the Blockstream guys are highly competent coders and cryptographers, they were before they formed Blockstream, and they are today. Your placement of trust in them thus far is not alien to me. However, a conflict of interest is an insidious thing, it may start out benign, but under the pressure of investors, deadlines, and runway... may begin to allow a form of self delusion... a self reinforcing mentality that what is best for the company is best for the protocol.
If Back, Maxwell, Wuille, etc don't say exactly the same thing you did and encourage people to watch for it, I will be disappointed in them.
The investors that deposited $21 mil didn't do so out of charity, they were sold an eventual ROI. I'm not satisfied with the thesis that it was "we're going to altruistically contribute open source code to better Bitcoin, which will probably make us massive amounts of money somehow, and we'll dissolve the company while stiffing the investors if we have second thoughts about it."...
At some point for most people, money in USD terms probably becomes secondary to other goals and mostly just a tool. Most people will never know what that point is for themselves. A guy like Schmidt is probably at least as interested in things like his role in guiding the world through the technotronic revolution than he is in increasing his net worth by {n} million more dollars.
Back into a more typical scale, when I threw some fairly minor portion of my excess USD into Bitcoin I of course hoped that I would win in monetary terms, but I think it is fair to say that I was at least as interested in Bitcoin for it's potentially semi-revolutionary role in the future. I considered the possibility that anything would come out of my speculation to be low, and that anything which I considered 'good' would be lower yet. I have no trouble imagining Schmidt's calculations vis-a-vis his stake in Blockstream being similar.
...I want to know how they plan to make money, and if artificially crippling the main chain could incubate that plan.
I have been agitated since day one that the blockchain could be 'crippled'. By bloat, be it by organic means or a strategic attack. Once that happens it would be impossible to undo without some unpleasant and probably devastating compromises.
This concern about bloat has informed my own utilization of Bitcoin and my feelings about development direction. It is exactly why I am so positive about moving forward on ways to address the problem, and as I've said before, 'subordinate chains' was the thing that hit me back when I finished reading the whitepaper in 2011.
I think it very probable that certain of the named names we are discussing here have the same set of concerns about the health of the blockchain as I do, and that it is a very good explanation for their work and ideas vis-a-vis structure of the blockchain. In other words, I think that they probably organized under Blockstream in order to address blockchain issues more than they address blockchain issues because they organized under Blockstream.
It seems that more distribution of available software is the only way to allow miners, who issue the votes that count, to fully exercise their built in right of voting with hashes. If the miners continue to choose core's direction, so be it, I'll convert my node to a segwit node so it actually continues to fully verify. I got interested in Bitcoin because it felt like there wasn't a central point of control, that it natively resisted control by centralized influence. I have confidence that the market will settle the blocksize just as efficiently as it sets the price and the difficulty, a market with production quotas is not a market. Mining valid blocks is not a trivial thing, and those doing it have an interest in seeing the system they manage be as successful as possible.
I've had a strong sense that it is desirable for everyone who uses Bitcoin to also support it in some tangible way from an infrastructure perspective. If this ever was a theoretically possible scenario, it died in the early days and I have to be practical about this. I've only briefly skimmed segwit, but it seems like a practical 'engineering' realization that the real world structure that I (and I suspect others) would would like to see is untenable. Seems to me a way of addressing the real-world flexibility problems while not necessarily permanently damaging the blockchain from a bloat perspective. At least not right this moment. My main concern about segwit is that the flexibility enhancements could make it more practical and likely to get stuck in the Chinese-finger-trap of bloat at some point in the future, but such concerns do not outweigh the benefits of potential progress on other fronts. But I digress.