No, it was obviously and flagrantly incorrect, as evidenced by the success of interchange formats that do allow for comments, including many real world systems that pragmatically allow comments even when JSON says they shouldn't. This is Stockholm Syndrome.
But what can we expect from a spec that somehow deems comments bad but can't define what a number is?
As long as they stay comments there's no harm. As soon as they become struct tags and stripping comments affects the document's meaning you lose the plot.
How do you feel numbers are ill defined in json? The syntactical definition is clear and seems to yield a unique and obvious interpretation of json numbers as mathematical rational numbers.
A given programming language may not have a built in representation for rational numbers in general. That isn't the fault of json.