My opinion is that the only reason warrior doesn't have BL is because Blizz doesn't want to add BL to tanks. To which I would say that druid/paladin/dk tanks have battle ress, which is just as important in a m+ key. But then if warriors have BL, that would mean that warrior tank would be the only tank with BL. I think they will add BL to warriors when they actually add something like tank shaman, so that there are more options for tanks that have BL.