Please don't take this as rude, but speaking more plain and directly than the previous person you replied to: I think they were politely telling you to come up with more substance in your comment.

The culture on Hacker News has historically been along the lines of, "if your comment is not more insightful than providing an upvote on the post, withhold it and leave an upvote instead." This was on the "welcome" page when signing up for a Hacker News account, and can be found here: https://news.ycombinator.com/newswelcome.html

See:

> The most important principle on HN, though, is to make thoughtful comments. Thoughtful in both senses: civil and substantial. ... The test for substance is a lot like it is for links. Does your comment teach us anything?

I think Hacker News comments tend to miss the mark on this test more often than not, to be fair. But it's perhaps worth at least politely pointing out when the substance test falls as far as, "this was essentially my approval of the more substantial parts of the post."

The irony of my comment is that I'm adding nothing to the discussion, myself. But hopefully there's some small value in reinforcing Hacker News' social ideals.