Why is sanskrit taught ?
Sanskrit is considered as god's language. It is a very pure language and has a lot of importance in many fields, especially, in the epics like Ramayana and Mahabharata. The Bhagavad Gita, which was the advice told by Lord Krishna to Arjuna in the form of a song, is was also sung and written in sanskrit.
Therefore, it is our duty to preserve such a spiritual and holistic language, and hence, sanskrit is nowadaya taught widely all over the world.