The problem is that the Anti-Materiel Rifle can deal an average of ~880 damage in a single sneak attack headshot, so there's no need to fire more than one round when sniping. So why does Bozar have to be the best long range heavy weapon or suited for end-game?
I think I'll reiterate what I've stated before which is that I think what Josh was going for was to integrate new weapons into the tiers to suit new playthroughs, characters/play-tyles, while not alienating every super powered weapon already available nor being the weakest of the bunch.