> I wish that neither parent nor child comment authors felt the urge to qualify and head off critical or clarifying responses.
I actually would go the other way and say that preemptively laying out a rebuttal to a common/superficial counterargument is an important supportive component of an argument. I personally wish that comment authors wouldn't take it as a personal slight when a common/weak counterargument is addressed preemptively.
Any scientific paper has a "what came before and why it's wrong and sucks, and why my approach is awesome and cool and better in every way" section and those are really the same thing - preemptive addressing of criticisms that reviewers/etc would make. You wouldn't say those are dismissive and superficial because they "belittle the previous authors and dismiss their work and arguments", or that "preemptively rebutting an argument is offensive to the reviewer". Why is that a bad thing?
"I am aware of a common concern X and I think it doesn't hold water because..." is a pretty reasonable thing to post in a casual debate and it really diminishes the discourse for people to take offense to it and for people to have to excessively censor or limit their discussion as a result. It's not good for the community.
Anyway, the other thing is, a lot of debates really come down to "values differences", which is a kind of X-Y problem. For example, in a political debate, a lot of debates over a policy aren't really about the policy, but rather a fundamental disagreement about whether government can (or even should attempt to) efficiently perform an action or regulate a certain kind of conduct. And preventing certain underlying ideals or principles from being surfaced in the discussion tends to lead to rather pointless debates where nothing is agreed, because it was never about the policy in the first place. So the policy actually worsens that problem as well, you just end up with tilting at policy windmills instead of addressing the actual area of disagreement (which is not the policy at all).