I do recall a thread where it was mentioned that even default users have the ability to lock their own threads, and will be allowed to do so if it isn't abused. This could come in useful if you want to post a link-list (like the ones Icelus has), post a fanfic, and possibly other uses.
In this case, however, I don't see it being very useful at all. A few reasons spring to mind, and here's how my train of thought went:
This forum is for general chit chat.
It's up to the moderators to decide what's chitchat, and what's off topic.
This thread was generally awful and boring to begin with, but that doesn't mean people can't post in it if they want to.
So... unlocked until further notice.