Because English is not the only language in the world.
You want to order something besides "Le Big Mac" when you backpack through Europe.
Be able to share your culture as well as language
It's a requirement for graduation.
To impress your date... or your mate
To develop a better appreciation and understanding of other cultures.
Some of the coolest movies in the world are not in English.
So you can relate to a lot of interesting people.
In business, speaking a foreign language will earn you trust, deals, and dollars.
Because our neighbors are worth getting to know.
So when you get that job as a secret agent, you understand messages like "A bomb has been planted in your briefcase."
So you won't be like Chevy Chase in "European Vacation."
Everyone knows Pig Latin, and it's getting harder to use it to talk about people
You are tired of this joke: A person who speaks 3 languages is trilingual. A person who speaks 2 languages is bilingual. A person who speaks 1 language is probably American.