Read the introduction to the persuasive essay, "should cosmetic surgeries be banned? " what makes this introduction weak?

A writer of a Persuasive Essay must include several convincing words ir order to show his position in relation to the situation presented (in favor or against), and thus try to persuade the readers. In the introduction, the word should is usually employed to ask  oppinions ou if somethig is correct or the best thing to do. It can be only an advice, but not a persuasive word, which makes this introduction weak.