If you actually read it, you would see that I speak only about old threads. If a thread had been there for months or even years, what is the purpose in deleting it? Did you inadvertently miss that point or specifically chose to ignore it?
Sometimes deleting old threads are just as appropriate as deleting new ones. Think back to all of the shit threads that got removed, such as the ones that hilariousandco mentioned:
The only big ones I've ever trashed are utter shit threads in gambling discussion or off topic like is 0.002 bitcoin a good amount to gamble with or what time do you wake up in the morning etc after they have quickly been spammed to death.
I agree.
Do you honestly think that leaving these threads readily available, and thus enabling spammers to bleed the forum, is something that should continue?
-snip-
He suggested to lock old threads instead of deleting them.
I think trashy old threads need to be deleted so people won't participate in such threads again which could reduce trashy/spam threads/posts.