People have been martyring themselves since the year dot, and while I'm not in favour of it it's not a completely stupid gambit, since people remember martyrs, and whether or not it makes any sense tend to see them more sympathetically(*). Look at the feminists who threw themselves in front of horses, or went on hunger strikes etc.

(*)Suicide bombers may not get much sympathy here, but I get the feeling they do in the middle east, which is where they're trying to make an impression