Since everyone here are users just like you and since speculation on Apple pooicies is not allowed, no one here can answer "why" questions
I guess the bigger question is why do you care - just ignore faces if you do not like them
And if you are not capabile of ingnoring them then do not use iPhoto - in iPhoto you can not disable them - and that is the way it is
Lots of people here can help you use iPhoto - no one here can change it
A while back this method was posted by lopezion which many tried and said it worked:
Dec 30, 2013 9:06 AM (in response to mkmichaelmk)
Start of solution:
I did some digging in the prefs of iPhoto and found out the following. This is how you can disable (turn off) Face detection, without deleting faces found so far (just in case you want to restart processing at another time):
1. Quit iPhoto
2. Open Terminal Application (Applications/Utilities/Terminal.app)
3. Type the following (exactly as is):
defaults write com.apple.iPhoto PKFaceDetectionEnabled 0
4. - Start iPhoto - Faces stops getting on your nerves...
If you ever need to re-enable faces, just do the same again and replace the 0 with 1.
The procedure described by Old Toad is working for me. However, I'm also using iPhoto 08 which does not have faces. I use this version because most customers require keywords to be located directly below the image as is done in iPhoto 02-08.
Apple has announced that iPhoto is being discontinued. Hopefully the new software will be more to our liking.
The Terminal command posted previously didn't work for me, unfortunately.
But I figured out another simple solution, that doesn't actually turn off Faces,
but that does stop the annoying "Unnamed" bubbles from popping up all over your photos - which is all I needed:
1. Close iPhoto, then right-Click "iPhoto" app icon and "Show Package Contents"
2. Browse to "Contents/Resources" and look for the following files:
(The "face-tag" files are the individual parts that make up the annoying "Unnamed" Tags/Bubbles which are overlayed on your pics.)
3. Make a Backup copy of these files in case anything goes wrong:
Hold "Alt" while dragging the files to a new folder on your Desktop (Call it "Original Files" or similar...).
4. Duplicate the folder you just created and name it "Modified Files"
5. In "Modified Files", open each of the TIFF files individually in the "Preview" App (Strangely, Photoshop didn't work for me)
6. In Preview, for each file:
- Select all (CMD-A)
- Press "Delete" to delete the graphics
- Save (CMD-S)
7. Copy the modified files back into the iPhoto "Contents/Resources" folder where they came from.
You wil be asked to enter your Admin-Password for this.
8. Open iPhoto,then open any Photo with a face (or a group photo) and see it in it's full glory, without Face-Tags overlayed on the pic.
(If anything went wrong, just close iPhoto and copy the files from your "Original Files" folder back into Contents/Resources.)
Basically iPhoto still continues to do what it did before, but as all the "Face-Tag" graphics are empty now, you won't see any of it.
I've been annoyed by this for over a year (especially when looking at a group or party photo) and just signed up here to post this, so I hope this helps others as well!
(No guarantee if anything goes wrong!!)