What offends you may not offend me. And vice-versa. What serves no purpose for you, may serve a purpose for me. Be it intended offense, or otherwise, or both at once.
No one in the USA has the "right to not be offended." Being offended is subjective. It has everything to do with you as an individual, or as part of a particular group; it varies due to your moral conditioning, your religious beliefs, your upbringing, your education; what offends one person or group (of any size) may not offend another, nor a person of another grouping; and in the final analysis, it requires one person to attempt to read the mind of other persons they do not know in order to anticipate whether a specific action will cause offense in the mind of another.
And no, codifying an action in law is not in any way sufficient... it is well established that not even lawyers can know the law well enough to anticipate what is legal, and what is not -- any more than you can guess what is offensive to me, or not.
Sane law relies on the basic idea that we try not to risk or cause harm to the bodies, finances and reputations of others without them consenting and being aware of the risks. It does not rely on the idea that we "must not cause offense."
Law that bans something based upon the idea that some individual or group simply finds the behavior objectionable is the very worst kind of law, utterly devoid of consideration or others, while absolutely permeated in self-indulgence.