Question: why laxman cut surpanakha nose?
Answer: To punish her for insulting their machismo, Lakshman cut off her nose. To justify the lex talionis and to protect Rama and Lakshmana's stature as demigods, the scene was rewritten to portray Surpanakha as “the woman who deserved to be punished”, thereby also satisfying parochial male sensitivities as well.