Why Comment?
Crooked Timber had a quote about comments that pretty much reflected my own experience, “The number of comments a post gets is not, in any way, analogous to the importance attached to the post by commenters. … Comments are not a reflection of how much your audience cares about a topic. They are a reflection of how much they have to say on it.”
Since I started this site I’ve been amazed at my inability to predict what kind of content people will comment on. When I think I’ve written something super interesting it will get no comments and then when I think I’ve written something super throw away, it will get fifteen. I don’t think that’s a good thing or bad thing, just a thing. I generally agree that the more out there a post is, the less easy it is to respond to and that probably causes people to abstain. I also think I’m going to go with something similar to the comment system Buzzfeed has when I redesign this site (coming really soon). In addition to text comments, they now have “reactions” which you can choose from a pre-populated list (for them it’s like, LOL, OMG, CUTE!, etc. … Probably be a little different here.)
Hi, I'm 
Just: like!
LOL! OMG! CUTE! LIKE ROTFL!
ah, but you knew your post about comments would get comments!
I agree that when you’ve written something more ‘out there’ or complicated, somehow there’s more pressure on the comment to live up to the post – which is why you get fewer comments. whereas when you’ve written something simpler, comments can also be simpler – hence more of them. so I actually think that if you implemented ‘reactions,’ you’d get lots of thumbs up and OMGs on the ‘out there’/complicated posts, because this option would enable readers to respond without having to concoct an appropriate comment.
and actually, I’d Love a post on what you learn from this – how it helps you better understand and possibly predict what your readers enjoy.
@stephanie: ISF (insightful)! XFR (excellent follow-up recommendation)!