Simple scripting is not as difficult as making a hardware codec work. And simple scripting for automation does not go deep enough to really f*** things up. Maybe people would script some weird stuff, but then again, they could also wire Reason up in weird ways, and turn Reason's knobs in weird ways.
As I said, of course scripting is not for everyone, and it does require some days of learning. But if that would be reason enough not to provide people with scripting interfaces, there would be no software on the market doing so. But there is