The comment can be considered a meaningful contribution as well. Dialog is not only information but also flow enablers and/or facilitators. The fact that (s)he expressed sympathy/approval might show that others think the same, which in itself if a tidbit, if not too small. But it can greatly help others to chime in and relate or expand.

If you block these expressions then you get a lecture/dissertation, chock full of info, but not a dialog within a community.

So the question is: what do you see HN to be: a knowledge repository or a place that allows technology-minded people to share and belong?