Using language that accuses or offends readers is not effective in a letter to the editor.
When you write a letter to the editor, you want to make sure that you are able to capture the reader's attention. You should state what the letter is about and why it is important. You should use evidence in the form of facts and make sure that any opinions are supported by personal experience. You want to make sure that you are being polite and want to avoid language that accuses or offends readers. Your goal is to help someone who has an opposing opinion understand your view, not to alienate them.