It is not an either/or - you can both vote and reply.
Thoughtfulness has little correlation to the quality of a comment. A one-liner from a subject matter expert is worth more than an entire paragraph of mere hearsay.
If you replied with a correction, it's implicit that you disagree, and then downvotes would be redundant.
I think one liners, unless they are reminders of something that's universally obvious, are worse than no comment at all, because they can't contain much information.
Thoughtfulness has little correlation to the quality of a comment. A one-liner from a subject matter expert is worth more than an entire paragraph of mere hearsay.