I hate to admit as a Muslim you fellas are right in most things about radicalism and that terrorism from groups claiming to be islamic. But I would like to stress the importance of culture in the Islam.
I am not trying to blame a whole race but usually these groups are sponsored by the rich sheiks from the Arab peninsula. Also look at any violent fueled sects in the Islam they all come from the Arab desserts. There were times that tribes that had no contact with the Islam where being hired as soldiers and had to change their religion. These tribes formed the backbone of the Wahabbi sect of Islam. These guys are so cruel they have been known in earlier stages of their sect to burn down Islamic settlements and even mosques. This sect came in existence during the time of Napoleon(1800s) I think. Up untill then Islamic empires usually were the same as their western counterparts regarding violence, maybe even more tolerant.

Now we see that Saudi-arabia is from the Wahabbi sect and they are big time into training and funding radicals. For example the Bin-Laden family. Most of their leadership comes from the Arab peninsula.

Now there is the cultural aspect. Just as the west had their different ways of interpreting Christianity we had the same with Islam. Every part of Islam from north Africa to China is different. When was the last time there was a Kurdish IS terrorist, an Uzbek spokesman for Jihad, A Turkish suicide bomber, A terrorist cell operating in Bosnia?
My family is from Turkey and if you tell anyone over there about the 72 virgins and suicide bombing thing they will smack you in the face. Look at IS they target Turks and Kurds in Iraq, one reason is we look at different ways regarding Islam. I now many North-African guys that hate on their own kind, because they have moustaches. They believe that moustaches are signs of the unbelievers, in turkey(99% islam) it is one of the most normal things.
My relatives drink alcohol, even tough it is not allowed, in one way to ,me at least, it shows that a Christian and Muslim don't differ. According to these radical groups we are unbelievers, I think we are just humans who sometimes make ''mistakes'', but like I said we are humans, WE DONT BLOW UP INNOCENT PEOPLE for a bearded guy hiding in a cave who tells you what Islam is.
Just wanted to say that we are not like those assholes and yes radicalism is a problem stemming from Islamic sects not the whole of Islam.
Sorry if I was A bit unclear as English isn't my native language.