The really stupid thing is that even if they succeed, which is extremely rare, terrorists that bring the world down around them always end up replacing it with something more hideous, more evil. Their means defines their being, which generally places them deep in the sewage with the other lessor humans, a pool for all those creatures that failed to make the leap from animal to person.
And worse yet, are the fanatical ones, whose own simplistic selfishness deludes them into thinking that their deranged view on the world could somehow improve others lives, rather than as is clearly obvious, make them more miserable. The world is always far from perfect, but it takes a truly dense malevolent being to believe that more rules, strictly enforced and less freedom will do anything but pour fuel on that fire.
It's even hard to believe that some of these people are swayed by martyrdom, or some moronic lie about a harem of virgins in the afterlife, causing them to trade their one and only real possession, their life, for a foolhardy chance to ruin the world for everyone else. The idiocy here is sub-human.
We all sense the world is out of control and many of us want the honor of fixing it, but random acts of terror only contribute to the problem. Even a successful revolution, one that sweeps thought the population and purges all the nay sayers, is nothing more than collected evil, with a nasty purpose. Violent revolution is always bad. It's just too many selfish people trying to take the easy way out, instead of fixing the problems around them. It's stupid and cowardice, and ultimately history always looks down poorly on all of those involved, whether they think they've won or not.
Terrorists, no matter what the outcome, sit in the depths with the worst of humanity including tyrants, serial killers and warmongers. These people all trade their own satisfaction for the misery of others, the very worse trait a human can posses.