"Adults serve as employees." Freedom of speech would probably make schools disastrous. Everyone needs a peaceful place to learn and do their homework. "A public learning institution requires a peaceful environment to thrive."
Students also have their rights to say what they want. Without having a limit then we would not achieve what we need to. "They must achieve academic excellence while obeying various laws, rules, and regulations." When we are in school we still have to follow the rule of the law, and even school rules. Some schools though have freedom of speech. "Private and parochial schools, however, are not similarly restricted by ideas of individual rights, free speech, and other liberties." You can still have your rights at some schools, but the public is