I believe extremist Christianity is currently held back as most adherents with any wealth and power live in democratic countries (I want to keep it that way, I know they are recently trying their best to undo progress, see the USA).
However, obviously Islamic fundamentalism is causing many more problems now. Over the course of history backwards values and religious fundamentalism of all kinds have caused much bloodshed, Christianity included.
There was a time where the Arab world was rather more advanced than the Western one. For instance the scientist Ibn Al-Haytham was the father of optics. We use Hindu-Arabic numerals in mathematics in the West for a reason and the Islamic/Arab world were the pioneers of algebra. Also, religious freedom was protected and the Islamic world was relatively liberal and tolerant in the Ottoman Empire (at least in the early/mid period). I am not saying it was good by modern standards, I am talking relatively.
I deplore intolerance and backwards values of all kinds wherever they come from, I do not have a romantic view of the past and want us to always strive to improve and go forth in a positive direction which is why I am a progressive.
I hope Salman recovers quickly, I very much support and admire his principled stance on freedom of expression and I applaud him for his courage.
en.m.wikipedia.org
en.m.wikipedia.org
Karen Barkey, Islam and Toleration: Studying the Ottoman Imperial Model, International Journal of Politics, Culture, and Society, Vol. 19, No. 1/2, The New Sociological Imagination II (Dec., 2005), pp. 5-19
www.jstor.org