If I send SmartMarket Steem10 for a post, I get back (usually, but not always) my Steem10 plus a ROI of between 5% to 10% (in other words, 0.50c to Steem1. )

So you're essentially guaranteed a 5-10% ROI on every post you make? Do you not see this as a problem? Is this not virtually risk-free for you?

I understand that curators (and users in general) have mostly disappeared - and that's a problem with incentives, interface usability, marketing (the lack thereof), and the general downward direction of STEEM prices over the past year and a half. But what you're telling me is that any user can sign up, create a post, and then buy their way to 5-10% profits on an exploitation of platform incentives and rewards.

This is precisely why the system is failing us.

But because I treat the buying of votes as a part of doing business on Steemit, I am destroying Steemit?

I'm not sure that posting content and buying votes for it is "doing business." And I don't think it's you or people like you that are "destroying Steemit." It's the package of protocols that were pushed and implemented in 2017 that are the problem - and the people who created and approved them. The protocols must be changed in order to correct the mistakes and restore balance to the system. That's not an attack on any individual or group of users. It's just the reality that we're in. I think too many people are trying to assign blame to regular users when their behavior today was just a natural and predicted consequence of adopting bad protocols.