This is what Eli Pariser refers to when he talks about a "filter bubble", although he uses it in a far more negative way.
I agree with this post completely. While I may not use the same language as @cryptoctopus in reference to tribes, I share the sentiment - each individual has their own interests, and has their own identity based upon those interests.
While Pariser may be correct in mentioning (as @juvyjabian suggests, in his idea of a trending page full of top posts on a diverse range of topics) that individuals need to have the opportunity to reach outside of their "filter bubbles", at the same time those "bubbles" still exist as our current reality - and, as is mentioned in this article, when that is ignored, people simply get bored, and they look instead to the myriad of other options on the internet that will do the filtering for them.
I truly believe this article reflects the next step for Steemit as a platform.