We rarely lock threads. There are various reasons for rarely closing threads.
For the most part, if one doesn't like a series of threads, they can simply not open them.
If there becomes way too many, then we'll deal with it.
Sometimes these topic issues come in waves.
Very little emotional trauma is being inflicted upon people through having to view the thread titles.
Again, if we see a huge build up on a certain topic, we'll deal with it.
Sometimes the drama and flack we'd get from closing a thread would just create more work for us. Of course not closing them creates work for us too.
Hmm..which faction do I want to get flack from today??? *ponders*