In our daily life, people are usually first exposed to vulgar language when they learn a new language because vulgarity is always short, easy to remember, and frequently used. Since vulgarity is also part of a culture, I do not oppose to learning vulgar language. However, to learn and to use are totally different things. Some students consider speaking vulgar language so cool and distinctive that they use it in every sentence. However, in native speakers' eyes, these students are just undereducated annoying, damaging the images of their countries.
Yeshuyi