I'm guessing because "it's cleaner/simpler", but that's a shallow understanding of those words. Just because there are two characters fewer on the screen doesn't make the code simpler. Simple semantics are what you should aim for and inconsistencies like these throw a wrench into that.

For example, strings in JSON vs YAML. Isn't it "simpler" to not have to quote every string? So long as your string isn't "no" that may be true. So now instead of a simple mental model of "every string must be quoted" it's "strings don't need quotes except for these specific exceptions that cause issues: <list>". So much simpler... sigh.