It just seems a bit overly controlling, heavy handed, and unnecessary.

If people are making posts that you as a mod find concerning why don't you warn them instead of abruptly closing a thread without some discussion with forumites that use the thread/enjoy its content. 

Why not put a post into the thread stating that the content is starting to be of concern - and give examples so we can better police ourselves? 

It's not just this thread: I find this undemocratic approach is the norm and honestly I believe some mods use it to dampen conversations which conflict with their own belief system (usually club support i.e Victory).  

You are the mods, it's up to you to manage this. However, I know the current approach irks a few forumites who actually contribute more content to this forum than the 442 magazine writers do.