Comment by thaumasiotes

I can't really tell what you're trying to say; JSON also has no representation for rational numbers in general. The only numeric format it allows is the standard floating point "2.01e+25" format. Try representing 1/3 that way.

The usual complaint about numbers not being well-defined in JSON is that you have to provide all numbers as strings; 13682916732413492 is ill-advised JSON, but "13682916732413492" is fine. That isn't technically a problem in JSON; it's a problem in Javascript, but JSON parsers that handle literals the same way Javascript would turn out to be common.

Your "defense", on the other hand, actually is a lack in JSON itself. There is no way to represent rational numbers numerically.