Why is the "In reply to" indicator suppressed sometimes?

[Antinous]

@codinghorror

In a normal dinner table conversation, after a lull when someone stops talking, the next person who talks is very likely to be responding to or continuing a thought from the last person who talked. That’s just how conversation works.

In real life, yes. Here, no. It’s completely decontextualized. It’s also a single-serving departure from the semantics that rule the entire rest of the page. It’s incomprehensible.

Here’s an example: New ebook DRM isn't just easy to break, it makes no legal sense - #3 by danimagoo

I can’t tell whether this commenter is critiquing the person above her or critiquing Cory.