With a steel ball, air resistance and the Magnus effect were apparently not an issue. Now I'm curious as to how it goes with either a ping-pong ball, or a golf ball and a longer drop to the floor.
I get the feeling that a one-dimensional view of directed/purposeful behavior (weak -> strong) is constraining the discussion. I do not think we can take as obvious the premise that biologically-evolved intelligence is more strongly directed than other organisms, which, in many different ways, are all strongly directed to reproduction, but it seems there are more dimensions to intelligent purposeful behavior. There are some pathological forms of directedness, such as obsessive behavior and drug addiction, but they have not come to dominate in biological intelligence. We generally pursue multiple goals which cannot all be maximized together, and our goals are often satisfied with some mix of less-than-maximal outcomes.
So, even if coherence does imply a force for goal-directed behavior, we have some empirical evidence that it is not necessarily directed towards pathological versions - unless, of course, we have just not been around long enough to see that ultimately, it does!
The problem with facts speaking for themselves is that they rarely do; on the contrary, they are frequently cryptic. That being so, perhaps the next-best thing is that people should be familiar with the dark arts of rhetoric, so that they are better positioned to recognize and respond to their use. The measure of credibility is only saying things that stand up to scrutiny.