It is of course the role of moderator to maintain some order on the site.
Nevertheless, it is useful to all to understand what order means, and what it is for. Understanding to some extent the motivations of moderators in their decisions helps maintaining order. Ideally, the situation is optimal when action by the moderator is no longer required because everyone understand beforehand what is proper and what is not.
For example, I am at loss to understand the decision of Otavio Macedo to protect the question Does the P versus NP conjecture in computer science have any direct relevance to linguistics?.
This protection is intended to prevent noise answers by new users. But there had been no such answer so far, 5 days after the question was asked. Indeed, that is rather a pretty quiet question. So why do it?
I feel personnally concerned as I was the last one to answer, 5 hours before Otavio Macedo's decision (the previous answer dating 2 days earlier), and I cannot help thinking that my contribution motivated him. But I do not see what is wrong with it. I also commented 2 other answers because I did not think they were adequate or complete. Is that bad ? What did I do wrong ?
And even if I have nothing to do with it, why this sudden decision ?
More generally, what should motivate protecting a question, especially 5 days after it has been asked ?