Social context affects a lot in Japanese- there is a multiple levels of politeness modifiers, there is all sorts of language that you would use at home but elsewhere. Some very rude stuff is actually acceptable in limited situations like around men or business people in drinking parties. Hence any question about language choice really needs a social context which a learner might not know whether it is relevant or not yet moderators are desperate to remove anything in question that is not the language question. Shouldn't they be directed to allow more content in questions? Social context is much more important in Japanese than English.
Looks like you're talking about this revision, which is actually an edit suggested by a low-rep user, and then approved unilaterally by a mod.
In one case, I could agree that the editor removed a somewhat-subtle-but-might-be-important context about "all Japanese staffs" might be a mistake.
On the other hand, the edit really improved the English grammar of the question, which is not less important, and such edit would and should be approved.
Now, since the approver was a mod, it's approved unilaterally before another reviewer had a chance (however, as an OP, I believe you had an option to rollback the edit after the edit suggestion was applied). In my opinion, the correct action for this suggested edit should be to "improve" and re-added the removed context, instead of only "approve".
However, I don't agree with your premise that the mod desperately removed the social context (unless you could provide more cases; 1 case is not enough to prove it). This looks like an honest mistake to me, everyone makes mistake, and mods are human too.
Now, looking at the answer, I'm not sure if the social context "all Japanese staffs" would affect the phrasing (but I might be wrong). Anyway, another editor (also a mod) had re-added the missing context.