Bungie screwed up the inventory by having rng rolls on the weapons. After adding crap loads of more weapons with the two expansions there was no more inventory space for all the weapons. In hind sight they could have left all guns with set upgrades and then updated the weapon inventory to be the same style as bf4. Imagine quickly changing your weapon load out in crucible by easily navigating your unlocked weapons in an easy drop down menu that takes no inventory space in the bank. It would have been a much better system but with all the rng perk differences between the exact same weapons that would never work now.
I hate the limitations of old gen systems. I still wonder how much better the game could have been if they didn't waste so many work hours on old gen compatability issues.
And it's been a while since I played bf4.. I turned that on the other day and forgot just how great it looks. All the plant life blew me away all over again since I've been so used to looking at destiny shrubs and spin metal.