Fundamentalism is not accidental but essential to Islam

A lady poet of Medina, Asma, daughter of Marwan, wrote a poem where she warned the tribes of Medina against the Prophet.
'Do you expect good from him after the killing of your chiefs/Like a hungry man waiting for a cook's broth?' she wrote.
When the Prophet heard this, he said to his followers: 'Who will rid me of Marwan's daughter?'
A follower named Umayr, eager to prove his loyalty to Islam, offered to assassinate her. This he did that very night while the victim was asleep with her youngest baby on her breast. The Prophet thanked him and told him: 'You have helped Allah and his apostle.'
We are told by Muslim traditionalists that the message went home and the people of the husband of Asma instead of resorting to retaliation, the customary tribal custom, 'became Muslims because they saw the power of Islam.'

Have none of these people ever heard of standing up against a bully?