Somebody said:
When your religion is directly responsible for over 90% of the terrorism in the world
Somebody responded:
Utter nonsense.
This article includes some interesting info.
Internationally, in 2014 32,000 people were killed by terrorists. Of these, 17,000 were killed by four groups, all of them Islamist (ISIS, Boko, Taliban, Al-Shabab). It's not easy to unravel how many of the other deaths were due to Islamism, but some of them were.
So, 90% of world terrorism, no. But a major component, definitely yes.
I suspect that the reason people find Islamist attacks so disturbing is that they are not isolated one-offs (like many lone wolf attacks) nor focused upon a local issue (like the IRA used to be). They are aimed at completely changing the world via jihad. When the IRA let off a bomb, the French or the Italians or the Canadians could go, 'Tsk, sad: but not our problem.' When jihadis spray machine-gun fire up and down a beach, or blow up a train, we all go, 'Shit. That's not very nice. And we might be next.' This is of course what they want. Well, part of what they want.
What's also disturbing is how willing these loons are to go after their fellow-muslims. Particularly muslims of a different stripe: in 2014 the single biggest terrorist massacre was when ISIS killed well over 600 Shias.