A full-page refresh when I vote on a comment would be jarring. That's what he's saying.
It's a reaction to the reality of the web, which is that Javascript is commonly used when it's entirely unnecessary, much more of it is often used than is necessary, and it's often used to abuse webpage visitors. Most on HN don't object to ajax-y bits of JS that make a page more pleasant to use.
You'll be taken more seriously if you don't engage in meaningless hyberbole. You could recreate the open-the-reply-page-in-a-new-tab behaviour of HN (with the context-preserving JS enhancement for the non-middle-clickers) with a few kilobytes of JS if you're doing it right.
That is the crux of the problem. Why is there this obsessive need to recreate what is already available?
> with a few kilobytes of JS if you're doing it right.
As experienced with PHP developers in the dark ages, that never works. It will be a choice between easy and incorrect or difficult and right. The majority will never do it right for various reasons. And the web will loose in the eyes of the users.
For exactly the reasons stated: to both support in-line reply without the jarring page refresh, and to be able to open the reply form in a background tab.
And I think what Rich wants/is working on is making it both easy and right, because indeed, otherwise it will never happen.
I just shift-clicked reply, and it works quite well. I might add a rule to my sway config to make the "Add comment" windows floating :)
In the end, everyone is different and has different needs. That's why I like standards: everyone can set their user experience as they prefer it (or pick a web browser that chooses good defaults for them).