It's not why is it
important.
Why is it
necessary
? Would you like me to ask you why English is important in our life? English is important because it allows us to communicate with others, Spanish may be a different language, but using it, we can communicate with other fellow Spanish-speaking people. About 580 million people speak Spanish.
If you somehow, were in an emergency, and only Spanish-speaking people were around you, you would have to also know how to speak Spanish to get help.