Point well taken.
But please bear in mind, I myself am fairly new to the software and its code. I should've pointed out, that I might be wrong about what I wrote there.
As for the word "community": I think the slogan tries to transport the idea of enabling you to create a community. Obviously, interconnected services are the way to go, nowadays. But from what I've seen so far, the core team (which I'm not a part of) is mostly concerned with making the internal community's (as in: your community in your forums) experience as enjoyable as possible. And finally: The sharing option is quite new, that's true. If I'm not mistaken, your request here is the first of its kind (i.e. sharing to other services than the big 3). It's a little bit like with every new road, where the tar is still boiling hot: It's bound to throw some bubbles. I'll wait a few days for any vetos to arise, because we are talking about core changes here. There;s nothing worse than breaking the core - then It'd be mayhem all around. Also a reason why changes sometimes take a while. I think it's in everyones interest to take some time and get it right, rather than doing it in a hurry and plowing everything over along the way. If that hasn't happened then, I'll jumpstart my steamroller and see what I can do. As stated, it's in my interest, too.
What, btw., do you mean by "buffer button"? This little menu attached to every post, right?