Such a response may be overly simplistic and naive. Actually, there are other, more specific reasons:
Qur’an:8:39 “Fight them until all opposition ends and all submit to Allah.”
Qur’an:9:5 “Fight and kill the disbelievers wherever you find them, take them captive, harass them, lie in wait and ambush them using every stratagem of war.”
Qur’an:9:29 “Fight those who do not believe until they all surrender, paying the protective tax in submission.” Qur’an:9:123 “Fight the unbelievers around you, and let them find harshness in you.”
Qur’an:47:4 “When you clash with the unbelieving Infidels in battle, smite their necks until you overpower them, killing and wounding many of them…Thus are you commanded by Allah to continue carrying out Jihad against the unbelieving infidels until they submit to Islam.”
Obsolete verses? That 1400 year old view continues to 2010:
- “Arab and Muslim regimes are betraying their people by failing to confront the Muslim’s real enemies, not only Israel but also the United States. Waging jihad against both of these infidels is a commandment of Allah that cannot be disregarded.
- “All Muslims…crucially need to understand that (what) the (Muslim) nation seeks can only be attained through jihad and sacrifice and by raising a jihadi generation that pursues death just as the enemies pursue life.”
- Egyptian Muslim Brotherhood leader Mohammed Badie, October 2010
"…democracy is…forbidden for Muslims…democracy (is) incompatible with Islam because the Koran insisted Allah was the sole lawmaker… humans have no right to make laws."
(http://www.news.com.au/national/islamist-leader-burhan-hanif-tells-aussie-muslims-told-to-shun-democracy/story-e6frfkvr-1225887784755#ixzz0slho45BW)
There's more:
Qu'ran 2:191 "Kill the disbelievers wherever you find them, and turn them out from where they have turned you out, for tumult and oppression are worse than slaughter."
Qu'ran 5:34 "Slay or crucify or cut the hands and feet of the unbelievers, that they be expelled from the land with disgrace and that they shall have a great punishment in world hereafter."
FWIW, because the vast majority of muslims are born into this totalitarian system, rather than choosing to be in it, they have never heard the Truth. For example, they will argue Christians used violence to advance Christianity through the Crusades. They don't know the violence of The Crusades was going against Christian teachings not embracing them.