Doing this, though, would take away my chance of participating in some discussions I otherwise would, as they'd be archived before I see them.
Increasing submission life to a month will mitigate that and allow me, and likely others, to reduce the amount of time spent on HN looking for interesting links and waiting/hoping for them to become successful so we have plenty of people to have a discussion with.
And there have been many threads on HN which I wish didn't die out so early, because there was plenty opportunity for it to grow further.
I'd like to read what the HN crowd thinks about this and what you like/dislike about it.
Do you have some examples?
I think 2 weeks is too long. After a few days, almost no one looks at the threads, and it's not a conversations.
If you see a example that is about to be frozen but it has still a live interesting conversation, you can send an email to the mods hn@ycombinator.com with an explanation. They sometimes do weird things in special cases.
(Perhaps the whoishiring threads should last until the next post.)