I agree with you. As a content consumer the value of steemit depends on the quality of its content. As a content producer the value of steemit only matters if the rewards depend on quality of content produced. That quality has intrinsic and extrinsic components, or perhaps we might say objective and subjective components. Objective may be the originality of the post, how well  content meets a certain information goal, etc. Subjective includes people's interest and feeling of the content, as well as temporal aspects, since some information is quite valuable only at certain times. However, if the economic incentives are such that we can treat content as a black box and the only factors for upvotes and rewards are how much someone can make from that black box, then content quality is irrelevant and the platform suffers, at least as a serious platform for content. It can still however, be a good platform for treating content as tokens, where the value of those tokens are based on factors such as how much power is behind the poster and the groups who will automatically upvote the token.  As I learn more about Steemit, I am constantly reminded of my favorite Hayek quote: "The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design." (From Hayek's "The Fatal Conceit: The Errors of Socialism")

Personally, I'm quite happy with what the platform has done for me. My fiction makes slightly more on steemit than it does on all e-book channels combined. Still far from the quitting my day job lever, but that is fine for me. But when I try to convince friend content providers who actually did quit their day job that steemit is a great platform for them to try,  there is one major issue keeping them from even trying and that is the inability to turn their following on social media into advertising revenues.  You could have a hundred million non-member pageviews on steemit and it wouldn't get you a single cent inadd revenues.

On the flip side, you can pay 20,000 SBD for 'promotion' and all it gets is a place in the promoted tab that nobody looks at ever. 

It seems so simple, really.  Combine the two as part of the platform. If a non-logged-in user visits a blog through a social media link, show some of the relevant 'promoted' content to that user. Then pay the blogger who brought in the non-member content using some of the money the people promoting their content brought in.  That way you lowe the threshold for the professional content creators to join the platform, pull in higher quality content providers and give the people spending money on the promotion feature a bit of bang for their buck.

I think if the platform solves this bit in this or a similar way, the gap that now gets filled by bidbots will disappear and so will the justification for using them as self-upvoting proxy.  If I'm correct about this, a facility (bidbots) that curretly has the unintended side effect of decreasing the value of the platform could be replaced  using simple means with an improved version of an existing platform facility (promotion) that would end up increasing the intrinsic value of the platform.

Hope I'm making at least a tiny bit of sense here.