Found this interesting article on Wired.

Suicide Bombing Makes Sick Sense in Halo 3

Clive Thompson talks about Halo3 online. As someone with a job and a family he cannot work on his Halo3 skills all the time. So he sucks compared to people with more time on their hand. He dies very quickly. His way of revenge is to suicide bomb. He dies, but his enemy does too and therefore gets no points.
It demonstrates, how having no chance for a future, can give suicide bombing an twisted economic sense.