New weapons with new perks, differently balanced, with new aesthetics, New elemental primaries that have different elements from the same weapon catagories as the ones from the previous raids... plenty of reasons one might aim for the new guns even if their are just as powerful (in high level play) as the current. New raid weapons will have their raid specific perks that make them more useful, but adding the ability to raise older weapons will allow you to keep your favourite weapons competitive in future and other higher level activities that otherwise leave them in the dust. To me, the new raid weapons aren't even really more powerful, they're just effectively, arbitrarily penalizing old weapons. If it wasn't for simply the attack rating, the only thing different about Glass and Crota raid weapons... is simply that they are different. Take them into Crucible and neither will really give you the edge, only preference matters. It's not like pitting a guy with common and rare gear against you, the guy with less than legendary gear is indeed at a disadvantage. Sure, defense and attack are normalized, but stat values and perks are not. Legendary gear simply has more and better stats and perks. These weapons are ALREADY just as powerful as each other... until you take them into higher level play. I'm not suggesting just make the new ones "for 10 strange coins, raise the light level", that's stupid easy.. There could eve BE a system where to upgrade old Legendary and Raid weapons, using a mat or currency only found in the most current raid. Your still pushing forward in the game doing, just now you'd have the choice of upgrading a weapon you prefer the performance of, or falling in love with a new weapon, or both.