I think you have a very good point, Bardan...some people ARE "obsessing a little bit about breasts". Some have grown to consider them as intimate body parts relating to sexuality, and can't do the 'mind shift' to deal with them as milk glands for babies. I have trained myself to shift back & forth, as the situation demands.
   If a young woman in a bikini accidently loses her top, it affects me one way...if she slips one side down to feed her baby, it is totally different. It is not even necessary for a baby to be involved...once, at a folk festival, (in the campground area) I was talking to 'young' lady who was obviously a free-spirit type. She decided she needed a different blouse, and with barely a "hope you don't mind", she stripped off her shirt and put on another one. For about 4.5 seconds her breasts were exposed...and I just mentally shrugged. I was mildly surprised, but neither offended nor excited, as she was making no attempt to do either one.

It IS important to work it out in your own head, and not expect some objective standard to exist to control all situations.