Let us not forget that there's nothing inherent to either Christianity or Islam when it comes to fundamentalism. Christianity generated the Crusades, after all...
I think that's an example of cultural relativism that is as dangerous to the West as the people who are anti-math or anti-science. It is part of the deluded unscientific mythology of the left just as intelligent design is on the right.
There are obvious differences between Christianity and Islam that make Christianity able to coexist with a modern secular state while Islam is showing all over the world that it can't. For example Sharia is a comprehensive legal framework that observant Muslims are supposed to put above the secular laws (you know the ones brought about by a democratic process). There is no such thing in Christianity.
Also, Jesus mythology beats Muhammad mythology hands down as an example to follow (regardless of how much if any of it is true). Jesus' teachings were generally peaceful and kind and never attempted to spread Christianity by force, preferring to suffer himself instead. Muhammad slaughtered and enslaved thousands, explicitly permitted murder, stealing and lying (as long as directed against non-Muslims), kept 13 wives, including a 9 year old one, in addition to sex slaves.
Yes, there are obvious differences in the implementation at the present time which can possibly change: can you imagine the Pope leading a frenzied crowd in the St. Peters square in chants of "death to infidels" the way legitimate Muslim leaders do, rather than urging them to love and respect their neighbor? But there are also many doctrinal differences that make Islam more dangerous which is why in literally every place in the world where Islam is in contact with another civilization there is conflict. Just look at the map.