> It's what an inch is in metric, rounded down.

I'm pretty sure your parent was asking: why that particular height? 1 inch seems wildly arbitrary.

And if the height is arbitrary, why the hate for the Vaporfly? What is the technical reason for setting the limit so as to exclude the shoe?

Agree with the sentiment.

1inch is sort of focal I figure. Kind of like so many people choosing random states to be 42