I think it's a bad idea. Threads basically "die" for me when they fall off the bottom of my "Comments" link --- or, at most, when they get one or two "More" clicks past that page.

This is helpful, because after a few days of participating in a thread, the quality of my responses degrades, and the number of people reading it declines.

I feel like time-limited discussions are part of the culture here.

(I'm aware of the irony. I just saw the timestamp.)