Very good point and I think the communities are really going to assist in that when added to this site. That will be a huge boom for steemit.
Another aspect to the niche is that one is able to leave better comments when he or she is interested/knowledgeable about a particular topic. An article on bee keeping would bore me to death and my comment would be foolish at best since I know nothing about the subject.
Comments are important...quality comments even more so.
Yeah, I think communities will be huge. One of the problems I had when I started was finding content I actually wanted to comment on. Building up a subscription list is a bit of a grind right now.
Because the great majority of activity on Steemit sadly comes from bots, and they are not trained to understand nor respond to comments... which is a good thing in my opinion.
They target the whale posts, and up-vote them to earn their curation rewards, and then peace out, which is really sad, but a problem Steemit has faced from the beginning and still does.
The solution: more active real-life people. Until they show up, expect Steemit to suffer in the comment department, or until Steemit developers implement sub-Steemits, which will really start getting people engaged in my opinion.