The fact it isn't anything wrong the way you say it does not make the world different, but for Thai people as it is to offend Thai. The woman makes a defamatory and insults human dignity.
In fact, it did not break anything. As you say, it does not make a different world. But it is wrong for Thailand Thailand tradition. The woman was making defamatory and degrading.
In fact it is not wrong. Just like you said it's not the end of the world. But for the people, it is criminal traditions, The woman's reputation and was insulted dignity.