Why not ISO 8601 format for date values rendered into JSON?

I was just going over the release notes, and noticed the bit about
timestamp and timestamptz now being rendered in a fixed ISO-8601-compliant
format rather than whatever random DateStyle is in use.  That's fine,
but I wonder why the same approach wasn't applied to type date?

regression=# set datestyle to postgres;
SET

regression=# select row_to_json(row(now()));               row_to_json                
-------------------------------------------{"f1":"2014-08-17T20:34:54.424237-04:00"}
(1 row)

regression=# select row_to_json(row(current_date));    row_to_json     
---------------------{"f1":"08-17-2014"}
(1 row)

Doesn't seem real consistent ...
        regards, tom lane