It's awesome to see someone with the clout that you have bringing up these relevant points. I've only been active on Steemit for about a couple weeks now, so I can't respond from the point of view of an experienced Steemian, but I can respond from the point of view of a gamer who "min-maxes" a lot.

I think the financial incentive is what drives the thoughtfulness behind comments (I'm doing it right now), but what keeps things in check is that, for the most part, there's a human factor that will curb incentives to abuse. Sure, someone can develop a voting bot that upvotes comments and builds up Steem power, but since the dev team have incentive to maintain the value of the platform, there'll be that perpetual cat and mouse game.

I also question how sustainable Steemit is in the long run, but the way I see it, I can use it as a means to develop skills that I want to develop as long as it lasts. One thing is for sure: I don't want to participate in the "Steemit circle jerk" that is understandably popular here (you've covered the reasons).

The key to making this platform popular to normies is to have successful posts that are in about crypto and Steemit and DTube. It's great to see you contributing to that.