The world will always have assholes.
But what those assholes do depends on how they feel integrated into society. We have roughly 2,000 gang homicides per year and far more injuries that do not lead to death. http://www.nationalgangcenter.gov/survey-analysis/measuring-the-extent-of-gang-problems
The way gangs prosper and have amazing recruitment ( 800,000 ) is these people feel disenfranchised not by 1 incident in their lives but hundreds over a period of years that slowly build. Then these people are then recruited and they feel like they are part of something bigger. Poverty does not cause gangs, dozens of issues cause gangs and each issue has an additive effect.
----
A gang that used to be quite prominent in the US was the KKK. It is now a far weaker and more marginal group than it used to be. What happened? Society said enough and it no longer became socially acceptable to allow the KKK over an extended period of decades (it did not change over-night).
Once the KKK diminished in power, the amount of assholes in the world did not diminish. But these assholes did not organize in a structure that increased their propensity of hate and violence, which created a mentality where they thought they could prey on other human beings.
----
The current struggles in the muslim population is much the same thing as the KKK problem. Tolerate the "middle extreme people" (1000 lashes for decrying islam) gives license to the nutjobs that murder other human beings. And murder has no justification ever.
Thus the Islamic world need to like the immune system limit the damage such assholes do by saying certain things are not acceptable anymore. Furthermore non islamic people such as the west need to show that they are not against the people of islam in general, just the nutjobs. If the west starts stereotyping all muslims with one brush you only cause a counter reaction, and these counter reactions only produce noise, and it is this noise that allows these assholes to gather together and feed it each other hatred and barbaric nature.
This logic also applies to the west and other groups, for murdering assholes exist in all places (such as the gang problem in the US). That said there are different degrees of severity of how prominent these people are as a percent of the population. Kinda like the human body, we always are being infected with pathogens that want to cause us harm. It is our immune system, our inherent proactive societal structures, which keep sickness in check most of the time.
Edit: I forgot this forum uses smileys and thus it converts my numbers into tinfoilhats.