I get your point, however I was recently on a trip in the US ( I am from argentina and my height is 5.4), with some friends of mine who are pretty average on our country (5´7 - 5´8) - these guys I have never heard of complaining about their height or not being able to get girls because of it, however they repeateadly said they all felt quite small in the US ( we where in NYC and North Carolina), I was able to see average guys where at least 2 inches taller than them, with many other being 4 o 5 inches taller.
Girls of course where much taller, I would dare say most of them as tall as my friends, according to what I saw and compared to my own height I would estimate white american women height for the US ( the parts I visited) is about 5´6
This being said I do understand people above 5´7 wanting to do this surgery if they are shorter than their local peers.
For me, gaining 7.5 - 8 cm will put me very close to my country average and make me very happy, but not near average for tallest countries.