I am a very private person, and also don't take the most flattering photos (in my opinion). I HATE being tagged in photos, so i always will untag myself. No one has ever said anything, but if they did, i would simply explain I'm not ok with my name being out there, as a lot of my friends have their pages (where said photos are posted) more open to viewing, i.e. friends of freinds can view photos, and so on. I know I can't stop friends from posting photos of me, and I can deal with that, but the tagging simply makes me uncomfortable.
I also do something similar when posting photos from way back that may make some folks uncomfortable if ALL my friends can veiw them, so I've simply set that particular album to where only me and that person can see it. Maybe a bit extreme, but I'd like to think that someone woudl do the same for me!