What makes this problem worse is the way this discussion is framed. People go straight into examining Muslims actually believe, interpretations of the Quran etc. It is clear that the majority of Muslims do not hold violent views and do not condone such acts of violence, and saying otherwise incites against and marginalizes a large population of innocent people who want nothing except live their lives normally.
On the other hand, the phenomenon of Islamic terrorism is not incidental or marginal and this problem simply cannot be ignored. Instead of focusing on Muslim beliefs, moderates/extremists and so forth, we should be looking at the political aspect of it.
Political Islam is a political ideology, one that is dominant or striving for dominance in all Middle Eastern countries (and in Pakistan). You have Wahhabi Political Islam in the Gulf, you have Shia Political Islam in Iran, Iraq and Lebanon and you have Muslim Brotherhood Political Islam in Egypt, Gaza, Turkey and Qatar. The continued failure of Middle Eastern states to develop a strong national identity or civil culture means that political Islam is the dominant political ideology. The political power at the hands of political Islam is the source of this issue. It's an ideology that uses nostalgia for the Islamic world's magnificent past and fears of globalization to force conservative, sexist, and intolerant values. For decades states that are ruled by political Islam have used this ideology as a way of exerting power. The problem is that religious extremism is very hard to control once it has been unleashed and impossible to tame, and this ideology has spread itself to every corner of the globe where Muslims are unhappy (including all of the Middle East and a lot of Europe). The numbers don't matter here. 3 people with guns can affect the fates of thousands. A dozen people with pilot training changed the entire world.
It doesn't matter if most Muslims do not partake in violence - the ideology is strong and durable, and the only way to fight it is at the source. As long as the Arab states do not create an alternative political ideology, political Islam would continue to be dominant and its violence offshoots would continue to cause damage around the world.