The true hacker solves the right problem. Expired links are just the visible problem. The real problems are more subtle: users voting up fluff posts, nastiness in comment threads...
I think this makes it more tempting to upvote something just after looking at the headline instead of after reading it, because one has to remember so much or use so many tabs or bear with going back to the front page and clicking next again.
I have no idea about everone's behaviour, but maybe expired links in the end also affect something like users voting up fluff posts?
I suspect the fix will result in a large change to the code base and you want to always own/understand the code for some reason. So if you can't fix it yourself, nobody is allowed to, either. That's fine--just admit it's your baby and you don't want to let it go.
So, the only answer that fits all of the parameters is that he's trolling us.
The change to the code base would be easy. You can increase the expiration timeout or keep around more closures. It would come at the expense of using more computer hardware, which is an elegant technique of scaling: you free your human hardware to work on more important things.
Is there anyway to penalise the people upvoting a fluff link? Mods have a 'fluff link' flag, and using that applies some karma loss to everyone who upvoted the post and puts a notice on their user page? (This is an ugly kludge. It's meant as a thought experiment rather than a serious implementation idea).
I have made some comments on HN which should have been heavily downvoted but which got no downvotes or even upvotes. I have no idea how this can be fixed.
Some people on HN have an aversion to down voting and flagging and will only use these tools for the most egrarious examples of bad posts. It would be good if people accepted getting and giving downvotes as a useful tool in running the site.
There's another problem with people responding to people who are effectively trolls rather than ignoring or downvoting those posts. I know there are few moderators with very little time. More mods is not the answer, but perhaps 'big downvotes' for those mods would help. Applying a -5 or -10 downvote to people posting aggressive dumb comments would help set tone.
Perhaps having links to all the guidelines (including the links provided to new users) under the submission box would be useful?
This way I can only blame myself when pressing the button doesn't work as expected.
Great lesson on prioritization!