The sum totality of all the issues raised in that post is not an esoteric edge case, even if each individual element is an esoteric edge case. If you haven't encountered any of them in your real code yet, there's two basic possibilities. Either you aren't using JSON very hard at all... or you
have encountered them and you just didn't realize it. You will, sooner or later.
I'm not saying JSON is bad. Personally I think the sloppiness that this post enumerates is part of its success, and part of why it has so much support in so many languages. The more you nail down the semantics, the harder such widespread support gets. Right now you get a nice subset of the JSON spec that works in a huge variety of languages, where the JSON support for a given language usually converts the JSON into something fairly native for the language. This wouldn't be possible if you nailed down the semantics as hard as something like Protobuf does. For instance, a ton of statically-typed languages will let you encode and decode integers into JSON. But JSON doesn't have an integer type. Strict JSON support ought to forbid integers. But it's sloppiness lets us all just sort of ignore that and get on with life.
If you have a need for precision, avoid JSON. And people probably generally need more precision than they realize and probably ought to reach for JSON a bit less often than they do. But on the other hand, the whole thing does mostly work, right? That can't be ignored.
I'm not saying JSON is bad. Personally I think the sloppiness that this post enumerates is part of its success, and part of why it has so much support in so many languages. The more you nail down the semantics, the harder such widespread support gets. Right now you get a nice subset of the JSON spec that works in a huge variety of languages, where the JSON support for a given language usually converts the JSON into something fairly native for the language. This wouldn't be possible if you nailed down the semantics as hard as something like Protobuf does. For instance, a ton of statically-typed languages will let you encode and decode integers into JSON. But JSON doesn't have an integer type. Strict JSON support ought to forbid integers. But it's sloppiness lets us all just sort of ignore that and get on with life.
If you have a need for precision, avoid JSON. And people probably generally need more precision than they realize and probably ought to reach for JSON a bit less often than they do. But on the other hand, the whole thing does mostly work, right? That can't be ignored.