pgstat SRF?

While looking over the statistics-for-functions patch
(http://archives.postgresql.org/pgsql-patches/2008-03/msg00300.php), I
came back to a thought I've had before - why do we keep one function
per column for pgstat functions, instead of using a set returning
function? Is there some actual reason for this, or is it just legacy
from a time when it was (much) harder to write SRFs?

If there's no actual reason, I think it would be a good idea to make at
least new views added based on SRFs instead....

//Magnus