Hugh,
You are entitled to your opinion, but thats not how I see it. The VAST majority of arab-muslims in the world are appaled by these attacks- stopping ALL arab-muslims using simulators would be discrimination in the extreme- if someone with black hair crashes a car when drunk, are all black haired people stopped from driving cars?
It's also worth noting that there are other terrorism groups throughout the world which don't consist of arabs. Take the IRA for example.
Like I say, not trying to cause a row, you're entitled to your opinion, but it sure ain't mine!