Right in a effort to stop all the off topic flaming, think of it this way.

In H1 there was a pistol, H2 was released and people had to get used to the BR. H3 had the updated BR with more spread on the shots and no hitscan on it.

Now we have a new game(Set before Halo 1) So no BR was designed so they needed to introduce something that would fit in with the competitive play as well as not being overpowered. Its a new game, your are going to have to get used to the changes once again.