It's only by virtue of prohibiting rudeness that it was struck down. If people are being disruptive or threatening, they could be removed under a different or revised code.

Getting up and saying quietly, 'Mr. Mayor you are a twatwaffle' is rudeness. Screaming the alphabet at the town hall because it keeps the reptilians away is disruptive, even if the person does not mean to be rude, and their speech not offensive in terms of content.