Why is it bad for open carry? Because he's exercising another of his inalienable rights - the freedom of religion?
I'm not saying I agree with his chosen religion's leader, but this is a slippery slope that you really don't want to start sliding on.
Besides, he wasn't brandishing or calling for Obama to be killed, so he was *legally* carrying. Beyond that, you have to take media reports with a grain of salt because they're more interesting in fabricating the news than accurately reporting it.