I agree that this is an issue with the lack of comment scores. If I see something I strongly agree with, I'm more inclined to reply with a "Yeah I totally agree" if I don't know what the score is than if I see it already has 100 points.
For what it's worth, my original comment to which you replied has 25 points.
Thanks, though I wasn't specifically suggesting it was an issue. I was only answering the question asked of me factually and the fact is that, yes, it does change my behavior in some ways to not have comment scores visible. However, I do not feel I have sufficient information at this point in time to draw conclusions or make value judgments in terms of "this is a good thing" or "this is a bad thing" or even "this is what is good about it and this is what is bad about it". (I personally like engaging people in conversation. Although I am aware that concerns about signal-to-noise are very valid concerns, I have long been baffled by people who join discussion lists/forums and then loudly complain about people talking too much. So I am not yet ready to say, yea, verily, stating agreement in place of or in addition to upvoting is inherently a bad thing.)
Meta answer: Though there are certainly times that I reply these days when I would have only upvoted if comment scores showed.