Because, as I said, saying that the number both has infinitely many zeros after the decimal AND that it also eventually terminates in a 1 is a self-contradictory set of properties. It's like saying that a staircase ascends forever without ever ending, and that its last step at the top is painted red. If the staircase has a last step, then it doesn’t ascend forever without ending. If your number has an infinite series of zeros after the decimal, then it doesn’t end in 1 because it doesn’t end in anything. Because it doesn’t end, period. The fact that you can sum an infinite series and get a finite number does not change the fact that's it self-contradictory to claim that a decimal number has never-ending zeros that end in a 1.