if the request to delete the topic came from the thread starter because the thread starter changed their mind, I will usually grant that request. its their post, if they changed their mind about it and want it deleted, its their prerogative as the thread starter. if we do not allow that, we will be discouraging people from posting. It happens, someone posts but then later changes their mind for whatever reason, be it personal, legal, spiritual, religious, etc etc
on this thread, I just noticed it was posted 2008, so most likely the reason for the lock is someone tried to revive a very old thread. as to explain why such threads are locked, it was to prevent those new members who keep on posting very very old threads just so their post count goes up, it has happened a LOT and there have been also a lot of bickering on the thread as a result, nagkakaron ng away in some threads since ang next na magpost sa thread papagalitan yung nagrevive tapos magrereply naman yung bagong member, etc etc
also, while gustuhin man na iinform ang mga thread starters on why threads are locked, there is simply no time to do such at times sa dami ng threads involved, especially when the staff at that time is doing cleaning up (locking/deleting threads to clean the section)