It's easy to blame Muslims, or radical Muslims, or fundamentalists of any type one wishes. Or any other label, group, or political divide our personal social group tells us it's okay to blame.
The reality is actually simpler, I believe. There have always been people for whom hate is their only reason to live.... or to die.
Such people often gravitate to positions or groups that empower their hate, giving themselves over to it completely. The Muslim religion is not the only one such people find a home in. Most major religions can boast of extreme violence done in their name. Hell, even Buddhism hasn't escaped the evil in the hearts of some people. It just happens that Muslim leadership around the world has created the latest and greatest place for evil to fester, hide, and grow.
Religion is not alone in this. Most every form of government known to man has found places for the darkest and most evil minds imaginable. Communism has slaughtered millions, using hatred to run blood by the river. Socialism has proven itself a premier home for the evilest among our species. Capitalism has not escaped either, having shielded and empowered many humans with dark souls. The green movement, drug culture, medicine, education.... all have nurtured their own forms of evil mindedness. White power, black power, brown power.... our lives matter and yours don't power..... every single group, culture, or belief system has at one time or another been a home for evil people.
You see, it's not the group... it's the people. The individuals who hate.... and hate.... and hate. Hate to the point where it becomes their existence. Hatred of other people with other ways, or just other people breathing air.
This hatred may seem the most evil and darkest part of humanity, but I suggest there is something worse. That would be those who seek power, who plan and plot, and who USE those filled with hatred to achieve their ends.
One can always.... always.... identify such creatures. They are the ones who tell us it's okay to hate. They are the ones who justify evil in the name of their cause. They are the people who apply labels, dehumanize, and fan the flames to fuel their own power.
THEY are the worst among us.