Let us avoid locking of the thread to the extent possible.
Only the threads for which someone posts is brought to the fore. The threads in which no one is interested remains buried under. After about 30 days of inaction, the thread get auto archived.
By premature locking, we are depriving non-admins - members and guests, their right to express their views. In the interest of right of expression of views of all the users of the site, I would request all the admins - old and new...
more... to desist from unnecessary locking of any thread.
Of course locking is necessary when the discussions are going haywire and hurting the peace of the sight. In all other cases natural end in the form of auto archiving is desirable.
I request my fellow admins to correct me if I am wrong.