Bias caused by fear of Islamic extremists
Imagine you are a jury member in a Mafia trial. You know that some prosecution witnesses have been intimidated into not testifying. You should think that the defendants are more likely to be guilty than you would if you looked at just the evidence presented to you.
Some undergraduates at Cambridge University published an article mocking Islamic extremists. Predictably, the students have had to go into hiding and face prosecution from their school and the UK government.
Many Western European academics and journalists no doubt fear expressing negative opinions about Islam. Some critics of Islam are being intimidated into “not testifying” against the faith and its followers. Readers of academic and journalistic writings will understand that many potential critics of Islam are censoring themselves. Thus, people should figure that there are probably some convincing negative critiques of Islam that are not being made because of this censorship. Western Europeans, therefore, should have a more negative view of Islam and its followers than would be justified by looking at just the evidence presented to them.
Yeah, if only there was a country in the world that was willing to TALK about a "Global War Against Islamic Extremism," much less invade a country or two in the Middle East. OK that's just a silly pipe dream, but maybe there could be media outlets willing to give any time or space to people who declared that Islamic extremism was the greatest threat facing Western civilization today, and worried about controversial topics like immigration and reproduction rates and threats to freedom of speech? Nah, another silly pipe dream. Face it there a bunch of guys living in caves somewhere who have the entire world by the balls. Including you, brave reader.
I don't think trying to correct your biases by reference to an unfalsifiable hypothesis is going to get you very far. "There are all kinds of good arguments against Islam, but they are not being made because everyone is terrified" is logically equivalent to the man who is spotted spreading elephant powder in Regent Street, and answers the policeman's objection that there are no elephants there by saying that the powder must be effective. You're arguing from lack of evidence to evidence, which is usually a rationalisation of one's biases.
Empirically, it might make sense if there was any evidence. But I can walk down to a bookshop and buy any one of numerous volumes on Teh Islamic Threat. Further, observation suggests that noisy anti-Islamic punditry (Martin Amis, Michael Gove) can be career-beneficial.