I can see why it would bother you, but kids like that would find an insult for just about anyone - at some point it will come back to bite them in the backside.
^ This is absolutely correct and the best life-lesson here.
People will *ALWAYS* find a way to hate/diminish/victimise/bully/envy another person.
You cannot change any aspect of your life to suit others or the cycle will continue regardless, and you'll feel far worse for it...
For example, if you have a crap car, you'll receive hate for the badge, condition or age of the vehicle. So you buy a new a car, and then get jealous reactions from others who cannot afford such a vehicle. You've bought a new car to resolve the situation, but instead made it worse as the critics realise they may have influenced you and have some control over you.
For example #2, ugly kid at school gets bullied for their physical appearance (due to some basic survival of the fittest mindset). Whilst good-looking kid at school gets bullied for their physical appearance (due to jealousy and perceived threat).
Most people can be nasty and cruel, but kids usually are more vocal about it. Adults on the other hand can be far more devious about it. This is the human condition and not unique to any country or populace.