You put it cutely, but consider: if someone has nothing left to live for, why not take a few of the bastards with him?
The Israelis have made Palestinians' lives sheer hell for years. It's really no wonder that some of them are driven to the point that they just don't care any more.
The same thing happens here, only we call them "school shootings", like the one where the boy in Moses Lake, WA, who had been tormented for years by the jocks, brought a rifle in and killed/wounded a bunch of people.
I had a classmate in high school -- reasonably nice kid and extremely intelligent, but he had terrible acne, braces, and was generally nerdy -- who was treated similarly. One day, one of the "jocks" walked up to him during gym class and, without any provocation or warning, kneed the kid in the balls. Just for fun. Must've been about ten years later, I ran into my classmate at a shop back home; his parting statement to me was something like "see ya, and kill them all!"
I have little doubt that if we were in high school today, he probably would be one of the schoolyard shooters. Or, if he'd been a Palestinian whose house had been bulldozed by the Israelis, and who had been spat on by them for years, that he would've blown himself up trying to take a bunch of them with him.