The danger is being overly optimistic about how long it takes to do that.

Things don't 'fall' normally around small cosmic bodies. The local gravity is so low that any lateral velocity has an exaggerated effect. The behavior of objects around asteroids is counter-intuitive, if not absolutely chaotic.

It's a completely controlled deflection method.

Because of this low gravity, we B612'ers talk about 'docking with' a near Earth object and not 'landing on' one.

We're sitting in a shooting gallery, with hundreds of thousands of these things whizzing around in the inner solar system. So it's just a matter of time.

But the question is, do I agree with it when it's 1-in-100, when it's 1-in-50, if it's 1-in-20. That is a policy question. At what probability do you begin to spend hundreds of millions or billions of dollars in order to do something?