Of course they do. Or if two people are disagreeing through multiple comments, you can tell as each person comes along as
every one of your comments will get a downvote (and, I'm sure, the person you're arguing with is probably earning an upvote). So you learn that if your opinion isn't popular, do no reply multiple times or you'll "pay the price" multiple times.
Even if your comments are long transparent, people need to "exert their opinion" and penalize you in aggregate.
https://news.ycombinator.com/item?id=8042707
There's a conversation where, in response to someone hailing an app developer for linking to competitors, I observed the benefits that such an action brings. I had responded to a couple of replies, and could tell as each person came through because they didn't just skip that no longer relevant, transparent conversation. No, they had to read it and then gang downvote. Which...what's the point?