Obviously I started this thread because I was "unhappy" with some of the recent actions of the MC. If uncivil posts occur, to me the "common sense" action to take is against the specific posts and posters. I see very little "common sense" in locking threads in response to the actions of some posters to it (versus locking or moving a thread whose subject or initial post would be in violation with the forum or subforum it was started in.) In what way does thread locking reduce future problems? I'm having a hard time seeing the correlation between action and hoped-for consequence. I do see posters who had NOT violated the policies get burned and upset by thread locks. I do NOT see the perps admitting to mea culpas and promising to change their behavior - probably because they aren't being punished.
I'll give you my personal perspective which may or may not match that of other MC members.
Threads where several individuals engage in (for lack of a better word) "uncivil" behavior tend to spiral out of control. Without face-face contact, it's often hard to communicate well. And it's well known fact in social networks (heck, any human interaction) to "attack back" when one feels they are attacked.
I suppose if we had a moderator watching the forum 24/7 with a hair-trigger to apply discipline as you envision, then it might work OK. Fact is that we don't have that ability as each of the moderators has work and other duties of life to attend to. In addition, we currently have a policy among the moderators to require a vote of 3 before taking action - that's in-place to ensure that more than one point-of-view is considered before we act & try and make the moderation "lighter".
Many times by the time the MC can act the thread in question has turned into a quagmire of "uncivil" or "political" posts. At which point closing the thread is the best option. All y'all can self-moderate without our action by simply refraining from the attack or political mode. From my perspective, that would make this a better place. For the record, we have banned some users either short- or long-term for violations of the RoC. We don't make that public for a variety of reasons.
There is nothing stopping someone from opening another thread on a topic, as long as it doesn't devolve in a similar manner.
PoA has continued to grow, while at the same time we've lost some legacy members who feel that the forum is too "uncivil". That's an issue that's not unique to PoA - anyone who's read the news this week would see that Twitter's CEO is struggling with the same issue in their feeds... and he's vowed to take action.
From my perspective, as the front porch of aviation, we want to be welcoming, while at the same time having a place for robust debate. Were folks to keep the focus on the topic being discussed (rather than making it "personal") it's less likely we'd be having this discussion. Saying "I disagree with your point because the agency is on record as saying..." is far better than saying "you're an idiot for thinking that. Any moron knows what the agency means". The former encourages discussion, the latter encourages a response in-kind.
Again, these are my personal views and the perspective I try and take when dealing with an issue. Sometime I get tired of the bickering and may well be cranky - that's why we currently have a policy that three or more MC members need to vote on a particular action (except for Spam, which can be dealt with unilaterally.