Ok, IMO people are pretty much entitled to do whatever they like with their own boobs. As far as I know MB doesn't have any exceptional psychological problems (given that all humans seem to have some). The only thing that bugs me about her choice is that every person who buys into the "bigger boobs are better so get yerself a boob job" mindset increases the cultural pressure on women and girls who haven't yet bought into it.
As you said, it's people's reactions that are the problem. Or, more accurately, the effect of internalising their reactions and taking them as an indication that there is something wrong with yourself. Personally, I've never found any correlation between breast size and attractiveness anyway.
Osmanthus, I agree to a certain extent with you here.
But it still comes down to a personal choice, maybe it's not a boob job but rhinoplasty or liposuction that people want to have done and if it makes them feel better than they should be able to have corrective surgery (within reason).
People also chemically treat their hair, add extensions and have artificial nails done, these are just a few of the non surgical alterations that the average woman does without giving it a second thought, does that mean that other women should avoid getting a manicure for fear that it will increase the cultural pressure for others to do the same?
Another example the current trend for women's bodies is to be rail thin, the fashion industry gave us Twiggy and Kate Moss as standards for what a women's body should look like, and many girls and young women torture themselves trying to be that thin, people diet and go to great lengths to loose a few pounds that do not make them look fat to begin with, yet we still have women who feel like they can never measure up.
The world isn't fair and the standards have been preset already, we can make adjustments or try to be happy with how we were born either way people will continue to alter their appearances.
It's important to raise our son's and daughters with a healthy perspective on body image so that they can make their own sound decisions about how they want to look and feel.