The difference being most BIS drops are accompanied with a decent loot table.
It's interesting that you think that when the most common feedback we get from droptables is "We want it like God Wars, a very scarce drop-table with a high value rare reward". Your comment would imply the opposite.
We want the Jaw to hold a reasonable value so we've made them harder, it wouldn't make sense to increase the droprate and negate the point of making them harder.