The reason is obvious. In order for new content to be relevant, the old content has to become somewhat irrelevant, otherwise there will be no interest in exploring the new content; hence no motivation to invest any time or energy into the new content. This is a loot based game. Half the fun is getting new, and better loot. Take Fatebringer for example (arguably one of, if not the most popular PVE hand cannons prior to TTK). Say you could ascend Fatebringer to 310 Attack. The only way to make a [i]new[/i] hand cannon worth working for would be to make one that is more powerful than Fatebringer, and since Fatebringer can be ascended to the same respective Attack, the only way to make a more powerful hand cannon would be to give it better stats/perks/mag size, since the respective Attack stats would be equal. Let’s call this new hand cannon "Ass Kicker" for the sake of discussion. Now, Fatebringer was already insane enough as it is, and now you've got an [i]even more[/i] powerful hand cannon: Ass Kicker. Can you imagine how OP it would be? Then imagine year 3; how are you going to introduce a successor to Ass Kicker, when it too can be ascended to the new Attack cap? Well, of course, the only way would be to, again, introduce a hand cannon with more powerful stats/perks/mag size than Ass Kicker, otherwise you’ll just keep using Ass Kicker, won’t you? Why would you bother getting a new hand cannon if it isn’t any better (or more relevant) than your Ass Kicker? Why would you care about the new content if there wasn't any new weapons/armour/loot that wasn't worth getting, or in other words, any better than the stuff you already had? Half the fun would be lost. Again, this is a loot based game, folks. If Bungie allowed us to ascend everything in existence, at what point/year would the newest “bestest” hand cannon need to have full ROF, full impact, full range, full stability, full reload, 50 mag size, and insanely OP perks, just to tip it over the relevance of it's predecessor? At what point does it become ridiculous, and contradictory? Bungie would end up having to progressively boost the stats and perks of new weapons to a stupidly powerful point/brick wall, just so you can keep their predecessors relevant in terms of Attack damage, when the predecessors are just going to be abandoned for their successors anyway, because they will have inferior stats/perks/mag size, making the whole exercise of ascending them redundant anyway. Is it making sense now? Can you see the pointlessness in trying to hold onto Y1 content? Do you see the logical flaw? Can you see the conundrum? Extrapolate the same logic into every other weapon that was considered to be one of, if not the best of its class. Again, the only way to make the new content relevant is to make the old content irrelevant, and in Destiny, what's relevant is the attack/defence, weapon mag size, weapon/armour stats, and the perks. Bungie had to choose how to make Y2 weapons/armour more relevant than Y1, and they chose to leave Y1 behind by preventing them from being ascended to the new attack/defence cap. This was probably the smartest way to go because it keeps the game play style relatively similar, and it doesn’t depend on having to constantly introduce weapons/armour with better stats and perks, which would inevitably result in weapons/armour that would be stupidly OP and that would inevitably hit a brick wall where it would just become impossible to make more relevant weapons and armour, whilst also allowing your Y1 stuff to still be relevant in Crucible. There is really no arguing with this. There is no way around it. The old content has to be left behind to make way for the new content. Bungie executed it in a way that is pretty reasonable and at least keeps your Y1 stuff relevant in PVP. As for the nerfing of some weapons, in some cases I think it was necessary, like Thorn and TLR, they [i]were[/i] a bit OP, certainly in effective range at least. And that's coming from me who predominately used those weapons. I loved them just as much as anyone. I don't think Ghorn needed nerfing, but it ultimately doesn't matter anyway since it was a predominately PVE weapon and it's been left behind. That sort of sucks but then again, why would I bother exploring new rocket launchers if Ghorn was still relevant in PVE? I wouldn't bother. Look what happened when HoW dropped. What was the first thing everyone ascended? Ghorn, so they could burn Skolas. It would be nice if the one exception was you could ascend Y1 class items since class item perks are relatively trivial and the trend with class items has usually been you choose them based on personal taste.