The reason it's counterintuitive is because the randomly chosen distance variable is 1 minus the nested randoms. Each random call becomes the upper bound of fut

The reason it's counterintuitive is because the randomly chosen distance variable is 1 minus the nested randoms. Each random call becomes the upper bound of future random calls, so the more times you nest it, the closer to zero you're likely to be. Subtracting that from one puts you close to the unit circle.