Knowing they're written that way on purpose doesn't change the fact that they're completely unlikable. Don't get me wrong, unlikabl characters can still be captivating and meaningful when the point of a work is to showcase that. The appeal of those movies is a glimpse or study into the minds of some reprehensible behavior. See: A Clockwork Orange.
But Farcry 3... the appeal to that game isn't really a study of some privileged kids dealing with trauma and such. It's running around the island exploding jeeps and taking bases and dealing with Vaas (i.e. the one compelling character in the entire game, and somehow more likable than any of the 'good guys'). The plot just gets in the way of you wanting to get to the second island and do more damage, or unlock more neat guns, and so on. Hell, I'd say even Farcry 2 has it beat. For all its faults and as bad as the malaria thing could sometimes be, it all still got in the way a lot less than in 3.
But Farcry 3... the appeal to that game isn't really a study of some privileged kids dealing with trauma and such. It's running around the island exploding jeeps and taking bases and dealing with Vaas (i.e. the one compelling character in the entire game, and somehow more likable than any of the 'good guys'). The plot just gets in the way of you wanting to get to the second island and do more damage, or unlock more neat guns, and so on. Hell, I'd say even Farcry 2 has it beat. For all its faults and as bad as the malaria thing could sometimes be, it all still got in the way a lot less than in 3.