Education in foreign languages in schools isn’t limited to students with English as a second language, you know. They teach foreign languages to kids who only speak English, or at least the middle school and high school where I went did. Some English-speaking parents choose to send their children to schools that teach in another language. I wanted to put my toddler in a Spanish-immersion summer camp (but there was no room for her). Nobody in my family speaks Spanish as a native language, I just think it might be a worthwhile skill for her to have.
Some students might want to get a job where they need to know another language. It’s not a bad skill to have on your resume. You’re complaining that schools want to teach students a skill that is in demand in the job market? Arabic is in particular demand by the government and the military. Schools should not teach subjects where it is useful for our government and our military to have a pool of people with knowledge of that subject?