They might think of that as crossing a line - from just hosting and enabling you to do what you want to do to actually telling you what you want to do.
How exactly does this happen? I can understand that some people don't understand the need to keep their private key offline, but I would have thought those people aren't really aware of the existence of the private key...so how does it end up in a github repo?
The last time for me was when they showed off the OIS and low-light capability of the Lumia 920. And the time before that was when they showed off the 41MP camera on the 808 PureView.
Both of which are far more interesting than them throwing up some schematics.