The karma of individual comments absolutely changes the way people interact with them
Not to mention it's a race to the bottom in terms of posting the most low-effort, low-quality content because they tend to get the most upvoted.
It doesn't do anything to encourage nuance or thoughtful interaction.
Correct, and a lot of it is posting either very short comments, which are parsed easily, or very long comments that seem like they are correct by length alone (Bardfinn and PoppinKream). Neither has much to do with being "good" comments