That's exactly my point, you deem Muslim terrorists as worse than anything else because they travel to western nations and attack there. Aka it's just because you value western lives more than others, or something.
I mean you ever hear of a little group called the Khmer Rouge for example? They terrorized millions and millions and killed nearly 3 MILLION in their reign of terror in a mere 4 years. There are so many instances of wanton killing and terrorism both by state governments, rebel factions, militant groups and political organizations.
In the last 2 years in Europe Muslim terrorists killed 443 people. In the US it's gotta be less than 100. Total worldwide including non-Western targets it's 1,200 killed over 2 years. It's 1,200 too much but the numbers give some perspective.
http://www.nytimes.com/interactive/2016/03/25/world/map-isis-attacks-around-the-world.html?_r=0
As far as say ISIS in Syria I couldn't find figures, they just breakdown Syrian deaths overall as around 450,000 and ISIS is responsible for a chunk of that. ISIS is a despicable organization, the way they terrorize populations in their caliphate and then their limited operations overseas that includes shootings and vehicle attacks. Their MO is as bad as anyones - killing innocents, torturing innocents and terrorizing populations.
But there is nothing special about their terror that makes it worse than other horrific terrorist acts. Their biggest difference is they travel more.