Very good article. I believe that boxing is defacto a more brutal sport due to the fact that blows are aimed mainly to the head and that alone suffices to end the argument without further points from both sides. Undeniably terrible injuries might occur during an MMA fight, but the head traumas have no comparison.
I think its that primal, raw brutality which only hand to hand combat offers,the kind of fight that we humans instinctively understand better, that has given boxing such huge popularity over the ages.