Ah, if you're interested in breaking out a thread within a thread... click the number ---^
The number is a permalink and shows the parent comment, the comment itself, and any direct replies.
I can't tell if you are misunderstanding him or her on purpose or not, but I'll bite:
When someone else on a thread posts a reply to a previous comment, but neglects to quote that to which they are replying, it is a bit non linear and confusing to subsequent readers of the thread.
It would be helpful and, in fact, wonderful, if instead of clicking on the "in reply to" link, we could just hover the mouse and see a little tooltip-style pop up of the comment which is being replied to.
As an agile user story:
In order to be able to read threads quickly and easily, following the flow of replies but not having to navigate away from my current view,
As a thread reader,
I want a tooltip style hover over box that displays the replied-to comment for any comments that are replies.