I've hammered a lot of questions, so you may be surprised to hear me say that moderators should use the mod hammer sparingly. I've also not hammered many more questions that I thought should be closed, that were I not a moderator I would have VTC'd without a second thought. This may be because I read a lot more of Server Fault than most people, and happen to notice a lot more.
In an ideal Stack Exchange site, the community decides what is on topic, what is off topic, what is horrible garbage that nobody should have to put up with, and moderators clean up only the worst of the messes.
How should a moderator lead? I still think a moderator should be:
- Editing posts. Improving poor English, repairing bad Markdown, fixing typos, or even completely rearranging an entire post to make it better.
- Leaving comments in abundance. Asking for clarification, giving pointers to related questions or external resources, explaining why a question is off-topic, etc.
- Answering questions. Which was one of the (unofficial) prerequisites for becoming a moderator to begin with. High quality answers are why people come here.
Hammering posts closed is less visible, and handling flags is almost entirely invisible, to the community, so these things - while they may be necessary - are not necessarily leadership.
Unfortunately, Server Fault is not an ideal Stack Exchange site. We have a narrow topic which is difficult for many visitors to comprehend. We have help vampires by the dozens on a daily basis. The barbarians are at the gate, and our community is near the breaking point.
I see no reason why a moderator should not be using the hammer when something blatantly off-topic shows up, the sort of thing the community would kill in ten minutes in the absence of a moderator. But, again, it's better, when possible, to just fix the question, ask for clarification, or whatever. When I'm not 100% certain that something would be closed anyway, then I don't hammer.
On the other hand, we've clearly passed the point where the community is willing or able to close everything that is off-topic on their own. The close queue is full of questions that often have their close votes aged out before five people even get to review them. Some people have given up on close reviews in disgust, mostly due to bad audits or sheer burnout. Those who do want to help clear the queue are stymied by the 20-review daily limit. And of course, many of these questions get low-quality answers before they can be closed and improved.
SF is at the point where something must be done now to improve the site's quality, most likely many somethings, or it's going to die. This can't be put off any longer. Mod hammering is at this point just putting your finger in the dike. We have bigger problems to solve and not much time to do it.