Should old topics be deleted from this forum?

[mcwumbly (Dave McClure)]

This seems worthy of its own discussion topic for the community here to weigh in on in the ‘meta’ sense (continuing the discussion from Notification when a moderator or admin deletes your message):

@codinghorror

I do a lot of deletion of old irrelevant topics from Feb '13 to remove noise from search engines.

@downey

This makes me very sad. Good open source projects keep a public history of decision making for the sake of Science. Also, search engines tend to discount old data that hasn’t been updated in a long time, so locking, archiving, and otherwise flagging information as outdated is much better than removing it altogether.

What kind of topics should be deleted from this forum? Should they be handled in some other way?