I'm guessing it may help bring JSON to use in the more restrictive companies that are scared of 'nonstandard' file formats. The kind that currently uses XML for everything.
Poe's Law; it's impossible to tell. There are presumably some companies who think that using XML for everything is appropriate, so it stands to reason that there actually are people who believe that as well.
More of a formality than anything else. Since JSON was already defined by Javascript, formalizing it doesn't really engrave the standard, it just gives it the recognition that its not just some whacky thing created by Dave.