Let's take context into account. The calipers had been set up very loosely before, and now I've come close to maxing out their braking power. I could move them out a touch for a bit of a compromise: more braking power, but less than I currently have now.

Also, they "grabbed" because I pulled the levers harder than I normally would, instinctually, given the situation.

Nonetheless, it proves your initial assertion false:

"That little initial millisecond it takes the rim brakes on my other bike to activate and grab--would have resulted in me hitting his car and flying over, and being very badly injured. This one experience convinced me of the complete superiority of disc brakes."

On aluminum rims, with tightly adjusted rim brakes, there is no "initial millisecond."

Also, there is no evidence that hydraulics stop any faster than rim brakes in dry conditions. This is a figment of your imagination.

Even with crappy carbon rims, stopping distances in dry weather is not very different.

Your hyperbole, fear mongering and lack of evidence are your undoing.