[[!comment format=mdwn
 username="http://joey.kitenet.net/"
 nickname="joey"
 subject="comment 1"
 date="2012-01-13T17:46:49Z"
 content="""
I don't think there are really any reasons, other than noone having done it. 

Although it is worth noting that using additional libraries/programs to eg, pull exif data and comments out of image files and make it searchable, does potentially increase ikiwiki's attack surface.
"""]]