Great post! I only disagree with one thing. The problem, in my mind, isn't decentralization, it's a flaw in steem's code / implementation. You have to look at this all through the lens of game theory. Right now, the rules of the system incentivize the abuse of the reward pool. These are problems that can be fixed, I've written many posts suggesting ways that would incentivize good behavior instead. (It's been a while so you'd have to dig through my older posts)
Anyway, the rest of your post is spot on.
You see the problem though don't you with that? It is engineering society again. Perhaps it is inevitable and i do understand incentivising 'good' behaviour but I also see where it will again lead, like it has so many other times. Of course, it will be a slow progression to actually change this world, if we don't destroy ourselves first.
I see your point. I look at it more as creating a system that is resistant to abuse by design. It is a similar problem that democracy is having now. We could just have a king /dictator (centralized) that could make sure everything runs smoothly, the problem is that as soon as the king goes rouge there is not much you can do to stop them. Where a decentralization of power is more resistant to corruption but the system has to be designed very carefully to make it last as long as possible. I will say that steem is one of the best examples I have seen but there are still some loopholes that need tightening as you pointed out.