The only reason I can think of, is to heal someone who is not given a Vuhdo Frame.

For example, you are running around with your 5-box team, killing crap or whatever.
And you'd like to have your healer heal some random person who is low.
Unfortunately, not being in your party or raid precludes them from having a frame within your repeater region.

Cannot really see a good reason for macros to heal your own team.