It really is all down to the fact that the dev team are natively Japanese, and the repercussions of that.

To get word to them, we have to have community reps take posts/opinions/ideas, dilute them down to actual questions/requests/actionable feedback, translate and pass them to the dev team, and hope to get a response. Hope because it's entirely possible there'll be a "You know, we have no idea so give us some time to investigate what this'd actually take and then we have an answer you can pass back" or "We're not ready to talk about this yet so don't say anything" etc. Hell, even if, say, people said "hey can we have x feature" and the community reps knew x feature was coming, they'd still need permission to talk about it if it hasn't been formally announced yet.

On the Japanese boards, there's just a lot faster turnover rate.