Why is it wrong (or against "the rules") for poems or writing to be autobiographical?

Rule book - what rule book? Do I care? Not one jot. If I want to write in the first person, then I will. If I want to write as she or him I will. I want other people to be able to relate to my poetry. I can write with some authority on the subjects I write about because I have experienced them. If some people don't like it because it is breaking the rules, do you know what I say? Tough!