My impression is that a lot of moderators on stackexchange sites overuse their powers. It seems they browse the site for fun in their free time, and close questions trying to find a reason. They rationalize that they are doing good community service but in my opinion they are effectively deterring new users and choking off the tiniest seeds of discussion when they do so. Thereby, they are preventing the creation of value on the site, which inhibits the growth of stack exchange.
Therefore, moderator powers should be used responsibly and sparingly. It is not something that is fun to play with when someone is bored. In most cases, other users who are more knowledgeable in the given topic have time to answer the question, before a moderator comes in and does harm by closing or deleting it, though I'm sure his intentions are good. This just results a lot of users leaving the site, and moving to other programming forums, (such as reddit), where moderators are more liberal.
I understand that moderation is a fine balance, because in too much noise the signal gets lost which results in ghosts towns. Therefore, moderation is necessary. But at the same time, too much moderation also suppresses the signal all together.
Here is an example of what I mean. I asked this question a few hours ago. https://softwareengineering.stackexchange.com/questions/128935/why-are-machine-learning-quant-researchers-paid-so-much It got closed by a moderator, because it's too localized. At the same time, another question was also closed by the same moderator, stating that it's not a real question https://softwareengineering.stackexchange.com/questions/128922/why-c-is-called-c-sharp
I cannot see why either questions are offtopic, other than that the moderator couldn't answer it, so he closed it. In the first case, I don't see why interviews are ontopic but salary is offtopic. This question concerns everyone with CS degree as they could apply for this job. That specifically includes programmers. In addition, machine learning quants are highly compensated all over the world, not just in specific regions.
Similarly, I can't see why the second question is offtopic either. In my opinion, it's a perfectly good question. Just because there's an answer for it on wikipedia, it's doesn't make it not a real question.
Anyway, this is my opinion and you can take it or leave it. I just wanted to draw attention to the dangers of too eager moderation that I have noticed on stack exchange lately