most of the blood being shed will be theirs.

Same reason people love Zombie movies. A chance for freedom from society's hypocrisy at the small, small cost of millions of others? If you're life is bad enough, who wouldn't take that risk when they feel they already have nothing else to lose. Of course, you've still got to push out the question... What if these dice come up wrong and you're the zombie instead of the survivor? That's a big risk they desperately try not to think about because if you think about it, even for just a second, then western society with its abundance of food and water starts to look like the better option.

It's easy to write it off as soulless. Or evil.

And I'm sure for most of them it is.

It's hard not to pity people who see the only option to their situation is to burn it all down. But the pity stops as soon as they try to rope others into their misery and delusions.