I tend to agree with your account of terrorism - it tends to be perpetrated by mean-spirited Arab immigrants to Western countries than by the oppressed masses. I think these guys do feel alienated - which is a common thing for immigrants (I know that from my own experience) - and express their alienation in a particularly nasty and destructive ways. They are typical macho men who express their own fears and frustrations by aggression toward "safe" targets who cannot fight back.
I started having doubts about this whole "blowback" theory a few years ago when I had a conversation with a can driver in Cape Town. As we were driving through the city, he was pointing to different vestiges of the apartheid regime (e.g. separate housing, separate facilities). I was surprised that he did not feel any anger or resentment, just and informing me in a matter of fact manner "how it was." When I asked him about it, he replied that he does not hold any anger, but he is hopeful for the future.
I saw a lot of those attitudes among South Africans I met, and that impressed me quite a bit. I also heard stories of the survivors of the Nazi concentration camps expressing similar attitudes. It dawned on me that people who really suffered usually want to forget rather than to fan their hatred and their desire for a revenge, let alone indiscriminate blowback. The latter is usually the domain of middle class "identity politics" fucks who use the suffering of others a justification of their victimization phobia and an excuse for their out-group aggression inspired by that phobia.
That is why I have no problems with these guys being hunted down and killed by any means necessary - just like President Clinton said:
"'We're not inflicting pain on these fuckers,' Clinton said, softly at first. 'When people kill us, they should be killed in greater numbers.' Then, with his face reddening, his voice rising, and his fist pounding his thigh, he leaned into Tony [Lake], as if it was his fault. 'I believe in killing people who try to hurt you. And I can't believe we're being pushed around by these two-bit pricks.'" -- George Stephanopoulos writing about the Somalia crisis in "All Too Human," page 214.
Wojtek