Why is Mongoose Bite even an ability?

What is really going to suck is when they give us a really fun rune next phase and have it share a spot that gives arcane shot, serpent sting, traps, etc some kind of scaling.

Once again making hunters chose from fun or doing 20% more damage.

Im running chimera shot just because of how boring bm is, but i know i will do more dps with bm rune.