The problem is that
1/3 doesn't equal .3333333333333
2/3 != .6666666666666666666
Slice something perfect 3 times and it has a very well defined edge and size. It's like that arrow problem that never reaches the target because it keeps closing "half the distance." It's bullshit. Using infinitely repeating decimals is the same as a 3 year old saying unicorns are real to justify why the living room looks like it was ran through by a horse.