Earlier quoted context omitted.
That seems counter to the "we want full access to our systems and hardware" position commonly taken on HN. It sounds very much like advocating for Apple's Gatekeeper [1] since it will keep unauthorized software from running on OS x. [1] http://www.apple.com/osx/what-is/security.html
Yes, you're right. And thinking about it, I think projectedoptics's solution is just better all-round anyway - why can you connect to the OBD at all while the alarm is armed?
If you couldn't, what would dealers (or anyone) do when a customer has lost their keys?