No, it’s just Islam. If there was anything wrong with ‘radical Islam,’ a majority of ‘regular Muslims,’ would not merely condemn these Sadistic atrocities—they would also take action to stop them. That never happens.
However, the new guy in charge of Saudi Arabia claims he’s going to do things differently. We’ll see.
That's easier said than done, when it's the militants who have a monopoly on the military weaponry, financing, better training, and murderous intent.
The average Muslim in these countries is dirt poor. Not to mention the consequences of failure—having one's family, frineds, and loved ones murdered.
Terrorists maintain their power by spreading terror. Expecting dirt-poor "regular Muslims" to magically do something effective about it is rather naive. Most of them are scared sh-tless of these killers. And when they do get the opportunity, wherewithal, or support to fight back, they often will.
You act as if every "regular Muslim" has a machine gun and grenades in his closet. If he's lucky, he's got enough food in the pantry for the week...