I would rate them a 0 (or 1).
22.5 / 799 * 10 = 0.28, rounded down to 0, or 1.25 on a scale of 1-10 (22.5 / 799 * 9 + 1), and it has declined further since then.
That was only for Survival Mode (which actually lost posts since I posted this in October, probably due to users deleting their accounts over the Twitch thing, and is nowhere close to regaining the lost ground even though it was only a couple thousand posts) but other sections have seen the same decline; the most popular edition by far is Bedrock ("Minecraft")? It has only had 1540 posts in its main discussion section since it was created in mid-September.
In fact, they used to have threads for chat but shut them down due to inactivity:
In summary, these forums are a far cry from what they used to be, and are probably a major reason why everybody says that the game is dying (I mean, if nobody discusses a game anymore it must be dead. Mojang's own sales and player count data say otherwise so something else must be going on; I know that a lot of former forum members now use Reddit even though it isn't really as good as a forum).
While the Minecraft subreddit is quite active, it seems more like a place for you to show neat creations that you've made or for posting fan art. That being said, Reddit could be why traditional forums like this are slowing down.
There's no need to visit a forum for a particular game or hobby when Reddit pretty much encompasses everything. Any popular games usually have a dedicated subreddit and it's not just limited to gaming too.
Enjoy cooking? /r/cooking is the place to be. Enjoy lifting weights, you have /r/fitness and for calisthenics, /r/bodyweightfitness has got you covered.
At this point, most people have an account on Reddit, so it's unlikely that they will continue to seek out traditional forums when there are already subreddits for everything.
I feel like that's a big part of why this forum is slowing down, but at the same time, despite strong sales, the game is definitely past its prime.
A huge part of these sales comes from the Pocket Edition too and we all know that this website isn't exactly the most mobile-friendly, so that could be another reason as well.