I know this is a bit late, but I missed this thread and felt like I should comment.
Firstly, this topic amuses me since I think I could count on two hands (maybe some toes) the amount of times we've had to lock threads in the 20 years this site has been running. So the assertion that we're trigger happy thread lockers is a bit of a stretch. Now it may be that some of the very small number of locked threads belonged to some people in this thread, and if that's true then I would suggest taking a look at your online etiquette and perhaps adjusting a few things.
You should note that we have very few rules governing each forum, where most other forums on the internet have a laundry list of do's and don'ts for posting. The reason for that is that we have an amazing community of professionals who actually like to help each other produce great work. Healthy debates are certainly welcome, but personal attacks are not.
tl;dr: If the topic descends to the equivalent of "no, you!", "heck you!" etc, then it is looked at as a lockable entity. Don't want that to happen? Don't behave that way.
M