I mean no offense by this, but from an SEO perspective why should steemit get the relevance for these posts anyways? The content is in the blockchain, it's not on steemit, and it's very likely that the same content will exist elsewhere on some other website using the same blockchain.
As a developer myself I understand why you want as much SEO relevance as you can get, don't get me wrong. It would help steemit grow organically. But you also have to accept that the content on any site site may exist other places and may not be unique. It's not always a bad thing.
Edit: to just close out that thought with my opinion - I don't think absolute copy/paste content is OK, it's kind of spammy and the only redeeming quality it could have is being a backlink. But if you use an asset that you're legally allowed to use (from elsewhere) on steemit, it should be fine, and you shouldn't get brigaded by down votes.
SteemIT is a frontend that is indexed in Google and other engines.
True that the content on any site site may exist in other places, a small detail here is that content needs to have supporting content of your own or it's basically worthless organically.