To me XML and JSON are actually technically quite similar, and both have been touted in their heyday for similar reasons over more apt format (auto-documented! simple to implement an ad-hoc serializer!).
Would you mind explaining why you thinks it is an apple and oranges comparison?
Tao3300
One is a markup language. The other is an object notation.
Clamchop
I'd say that's part of the calculus for comparison. Comparing apples and oranges isn't nonsensical if what you need is a fruit. XML and JSON are alternatives for many use cases, so you can evaluate if markup and schemas are valuable enough to be worth the added hassle.
Would you mind explaining why you thinks it is an apple and oranges comparison?