Additionally, people may be more willing to have these conversations if the comments made in old threads didn't impact their average karma. Long ago I decided I didn't care about average karma and just try to add something to a larger discussion or attempt to have a conversation in an old thread, but in the beginning I was concerned.
The back and forth comments deep in threads no one reads are some of the most interesting I have had.
That'd be nice, it explains why my avg karma is still less than 2 while I also get quite a few upvotes.
On the other hand, if I'm having a useful discussion with someone in an old thread, I often give them an upvote for their troubles as well. It's not like it affects the sorting or anything.
The back and forth comments deep in threads no one reads are some of the most interesting I have had.