Because it's one thing to complain about this (I hate it too), but flagging the submission for it is taking it too far

They’re being downvoted because HN spends most of its time writing that JavaScript.

So do I, I make half of my living writing Javascript code. Only my sites work when you visit them; you don't have to allow script from random 3rd party domains for them to work.

If you're making a content site then it should work without requiring Javascript. Or at least tell the user that they need to enable scripting, not that a random error has occurred.

The code that actually displays the content on the linked site is not third party - they're loading it from their own domain.

Also they do tell the user they need to enable scripting, or at least that's what Google Translate tells me "Oeps, je hebt JavaScript nodig voor deze website" means.