Let's assume Steemit is the only Steem client for simplicity's sake.
Steemit's need for Steem-centric posts
I came across this post from 
What drew my attention was the reasoning behind it:
"I will try to help optimize in such a way that helps the Steemit platform by attempting to appeal to a wider audience"
Surely diversity of content will not attract mass-appeal when there are better known, easier to navigate alternatives?
Steemit's value proposition is an auto-funded blog-based economy.
Moreover, mass-appeal will come from a widespread entrenchment in the credibility of this economy in the public psyche.
This entrenchment will come from general Steem advocacy, and clear information on the dynamics of the ecosystem - in other words, content about Steem is necessary for newbies to become sufficiently well-acquainted with Steem, that they can settle in this economy.
Moreover, as people increasingly participate in this economy, it stands to reason that what will be of utmost importance to them will be how to navigate this economy - as people seek to maximize economic return from Steem economic participation.
I generally feel as though diversity of content serves a decorative purpose.
But I think Steemit-advocates should be unashamedly push this novel economic paradigm.
The offer of financial freedom surpasses anything that another social media platform could offer - the credible promise for users around the world to obtain the wherewithal to live a comfortable life, on their own terms.
Consider this quote from the very positive Huffington post article:
"As far as user experience goes, Steemit feels more like playing a game (and gambling) than using a social network. Everyone’s betting on their content to be the next big earner, or clambering to be the first to leave that one great comment"
The author recognizes that content production is driven by the pursuit of economic return.
And the general focus of the article is not on the wealth of content available on the platform, because it's somewhat a red-herring.
It's not what has attracted masses of users, and I suspect it won't be what attracts mass appeal (for reasons stated above).
To say that a lack of diversity of content could inhibit mass-appeal, would be to place a value on this diversity so large, that it surpasses the positive value of financial rewards.
This doesn't make much sense to me.
People work everyday in jobs they dislike, because the financial rewards are sufficiently positive to counterbalance the negative value of working in an unpleasant jobs.