When I first joined Steemit comments were not rewarded, I argued the case that they should be because above all else, blog writers want comments.

Good comments can enhance a post, sparking debate that grows the original idea, or even takes it off into a whole new realm of thinking. I have lost count the amount of my articles that were inspired by great comments.

We are in the new age of informationalism, and the many currency is attention. Comments reflect an attention that goes deeper than merely reading the original post. It is a way to connect on a deeper level, I like your analogy about hooking onto intelligent conversation at a party and finding friends.

As well as being inspired by comments, I have found some great people to follow as well. Sometimes it might just be a 2 word observation on an article I've posted, that makes me think; "I like this person; lets check them out" :-)

Cg