Because riding a passenger doesn't really depend on the type of bike.
The things you want a passenger to do/not do is the same.  Ergo, if he's
asking advice, I reasoned he doesn't have much practice, period.  If
you say he does, fine.  I still wouldn't take the uninitiated up a
road that's all switch backs and reverse/center/uncrowned roadway, not
to mention the BDCs and squids who will also be on that particular
road.  He asked for advice, and even though it wasn't what he meant,
I still consider it some of the best I've read. 