Also, we should probably be careful in terms of using western/christian values as the perspective when trying to determine motive for that scumbag who drove into the synagogue.
I saw an interesting piece with a 'mideast expert' who suggested revenge was likely not this loser's motivation. Instead, she suggested it could be that once he found out his brothers had been 'martyred', he felt something like family peer pressure to keep up and also be martyred. Certainly worth considering, imo.