Do I think that anyone should stop anyone else from gettign PS? Ofcourse not. People should be able to do whatever they want to make themselves happier. Statistics have shown that most people that undergo PS do report higher self esteem afterwards. (Statistics also show that 42% of ps undergoers come back for more.)
My opinion on why PS is not the best way to create self esteem is as follows;
It involves a death risk factor. Low as it may be, it is still there. So when undergonig PS, you better be able to say that you accept the possible risk factors, and that your need for PS is so great that you will risk dying. This would indicate a great disatisfaction with ones self, unless this person also doesn't value life much.
Beauty (imo) is a perception. What is beautiful in one culture is not always beautiful in another. There is no black and white of beauty.
Yet there is a tremendous amount of beauty in ones natural state, as apposed to a plastic state. The features you wear are likely features reaching far back through generations of ancestors. At the moment of your conception, cells/dna was perfectly matched (in natures eye) to create the magnificently unique being called you. Perhaps that is a you with small boobs, or a weak chin, or a prominent nose, whatever.. but I beleive the process taken in your natural creation to be much greater than the process of a surgeon and a few instruments (though medical knowledge is also amazing.)
Ones natural state also reflects to some degree, the health of their life. For instance, ER doctors will often look at someones nails or hair texture to understand vitamin deficiencies, hormononal imbalances, and possible diseases. Your complexion, your weight, your muscle tone, your teeth, all indicators of how well you take care of yourself. Taking care of ones self is healthy, thus beatiful.
Because I believe the above to be true, I also beleive that a great dislike or non acceptance of ones natural being is unhealthy. The risk to alter it are also unhealthy. So it makes sense to me that the problem really lies within, and since surgeons are unable to perform ps on whatever thought processes or perceptions are causing the incongruence, that seeing a mind doctor might be a better way to go. Certainly less dangerous.