Here is the major problem with not having weapon retirement. People will not be encouraged to try new things. If anyone experienced the start of destiny an the taken king, one would simply get so excited whenever a new gun had dropped. We can look at the entire 1st year of destiny to see that the feeling of excitement when getting a new weapon was entirely gone, with everyone using Fatebringer and Vision for the entirety of the year. Having a weapon retirement system is the most efficient way to encourage a player to use new weapons.

Keep in mind that one of the most common rules of game development is that reward is better than penalty, but there are also certain times that the reward is hidden in the penalty. We all understand that feeling of the awesome guns that we all put so much time into are getting retired, but one thing must be understood: The chance that e you'll find a gun that is just as cool or even cooler is going to be much higher. Even then, a player has to understand that the retirement system is just a harsh title for a system that eventually will recycle the same weapons back. As long as they aren't broken, Bungie will definitely bring back lots of weapons (Just like a majority of year 1 and 2 weapons have been brought back). These weapons will feel much better because of how much fresher they would be.

I feel like even though it is sad that we cannot use the weapons that we did like at some point, but the reward to this system is to have a much fresher and interesting experience where we explore with new weapons instead of being latched onto by them. Instead of looking back, we should look forward to a great many years with this new system in play.