And why does someone feel ugly? It's because society tells them they are. If you are constantly mocked and made to feel like the way you look makes you inferior to other people then ofcourse you're going to feel ugly and rejected. The problem isn't in your head, the problem is in the way people treat eachother and in the way that the media portrays our society's supposed ideals and standards.
For instance, how many times have you seen, say, a shampoo ad with a picture of a real person on it (male or female)? They are always models with perfectly symmetrical faces with their own bodyweight in make-up and hair products applied combined with liberal use of the Photoshop airbrush tool in post-processing to make sure everything that could be even remotely considered to be an imperfection is removed (example). That is what we see when we look at an ad at the train station, open pretty much any magazine or turn on the TV. Sure it affects some people more than others, but we are all constantly made to feel self-conscious about how we look. Why do you think the woman with the dreamy blue eyes in any given toothpaste commercial has the most unnaturally perfect white teeth? It's because the very purpose of that commercial is to make you feel bad about your own undoubtedly less-than-white teeth and to pressure you into buying their product to quench your fear of being sexually undesirable. And this works, albeit mostly subconsciously. Any person that actually sits and thinks about it will pretty much come to the conclusion that it's entirely ridiculous but by the time the commercial is over you're already being bombarded by the next one so you're not really given the time to realise how stupid it is. Do not underestimate the power of suggestive and subliminal advertising and how easily the human mind can be made to override rational thought by appealing to our most basic emotions (fear, lust, etc.)
This affects everyone in western society to some degree (and hell, it's pretty much the driving force behind the whole advertising business), but again, some are more vulnerable to it than others. If you've already lived your whole life with being slightly odd looking in some form or another, then you've probably been bullied at school and possibly socially rejected in later life. Given all that it's kind of hard to just go "Oh this is all in my head." In the end it is all in your head, but it's our society that put it there in the first place. Saying that you are only ugly if you feel ugly is just ignoring the elephant in the room.
Ofcourse we cannot really fix deeply engrained missteps in our society like this by ourselves, so then all that remains is either put up with it (if you have the mental fortitude to do that, which some people do, and I admire them for that) or you can just give in and address the symptoms rather than the root of the problem by getting whatever deformity you have fixed. You argue that this won't fix your self-esteem issues but what are you basing that on really. Aside from surgical failures, to me it always seems most people who wanted this type of surgery for the reasons I outlined tend to be very happy with the outcome and feel better and more confident about themselves afterward.
If it makes the difference between being made to feel miserable and insecure for the rest of your life or actually turning your life around and making you feel better and more confident then don't the ends justify the means? Regardless of how revolting it is that we live in the kind of shallow society that essentially demands people to adhere to unnaturally high standards of physical appearance for no well established reason.
There are exceptions to everything
