It's asinine because you can mog a bow into a gun and they have different animations.
I agree, however, if you are MM at least, wild quiver procs use the original weapon animation so if you have a gun mogged into a bow, wild quiver procs will be gunshots and it can ruin the feel, making it good to follow suit. For MM anyways.
All of the best agi weapons are fists in ToT if I recall corrctly. Plus I'm a monk and monks can't see their fist weapons in combat. There are only agi fist weapons in the current tier as well. Blizzard has a fist weapon obsession this expac and it pisses me off.
fist weapons are my favorite. Shamans get a fist weapon for elemental/resto this tier! YEAAAAAAAAAAAAAH