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