Those thread that received 300 plus response should be closed, topics like "If bitcoin dropped to $1, what you do?" that topic received more than a thousand replies already and it should be clear by now to the OP what others will do "If bitcoin dropped to $1, what you do?" same goes with "Is bitcoin being used for illegal activities" also received more than a thousand replies and the most classic example is "How to motivate women to use Bitcoin?" with more than 2 thousand replies, there's more of them out there.
Those kind of threads are beginning to be a haven for account farmers and for those who are short with posts to meet the minimum or wanting to reach maximum post before cut-off date. Those should be closed.
It won't happen, but if such threads are going to be closed, there will be a flood of freshly opened threads by these farmers and signature posters.
If you close the door for them on one side, they will look for another door that will lead them to their destination.