Whether an action is offensive or not is not determined by the person taking the action, but by the person offended. If you choose to dress in blackface and actually have the intent of not offending anybody, it is still unacceptable.
Say, for example, I had no intent to offend but instead intended to display a healthy respect for human sexuality by walking around naked and performing public sexual acts. The fact that I meant no offense will give me little solace while I sit in jail for committing public indecency.
Your argument is silly.
