That would be great indeed! Some statistics (like the downloads of openHABian) are already available, while others would need to be collected. The meaning of these values is arguable…
The holy grail of that idea would be usage statistics directly from the openHAB installation, including setup size, used add-ons, etc. This is however a complicated topic as nobody wants to be tracked and monitored and there are (probably) legal issues we would have to take care of. Funnily enough, that could be done by yet another add-on
I love the map idea. Presentation of such a map is actually not too complicated, a way to add (and remove) users from that map needs to be done right. I’m again looking at the add-on idea above.
Another great feature derived from usage statistics would be a bindings sorting by install count and popularity.