They removed elemental primaries because they removed encounters where burns mattered. The only burn modifier is sometimes in the nightfall apart from a the few shielded enemies out there. And your argument of they replaced yr1 guns with yr2 counterparts only suggests that there are just as few choices as there were yr1. There will always be a meta in this game and I fail to see the wide variety of weapons and armor you speak of. Not that it matters because as I stated we just don't need elemental primaries so I don't see how it could adversely affect the game to still have them, not to mention the fact that particular perk sets are really what set some of the yr1 primaries off, elements just being the icing on the cake.