It's not really aimed at people managing other peoples Trello boards. It's for anyone managing multiple boards, that could be an agency with boards for each of their clients. But those aren't their clients boards, they are part of the agencies workflow and may be private from their clients.
There are other needs for things like this - I'd tried to build a system to get a dashboard view of multiple issue trackers, because as a consultant, I'm often having to deal with multiple client environments, and switching between multiple issue trackers is a pain. It was harder than I expected, and focusing just on value in Trello is a neat idea.
I'm also a consultant, and brought all my clients into Trello, at least for user acquisition projects (what I consult on). Having everything in one system makes life significantly easier. However, I still have to dig into each board to see what's happening, and even then there's no status dashboard; just an activity feed.