RPGs have the concept of Signature Gear. Your ancestral sword never becomes obsolete. The spaceship you won in poker game will never become scrap. If you wanted to ascend the khostav or stranger's rifle, I think you should be able to. That would be extremely cool. And no, I'm not interested in finding something "better". I have 4 or more pulse rifles from HoW that are at least as good, and reforgable to boot. I don't use them much. The legend of my guardian is inseparable from the legend of his weapon. That's what a legendary weapon is, after all, a weapon that is the focus of legends. And if I can't take it into Destiny's "brave new world", then I have no interest in going. Do I mind sacrificing other opportunities to make that happen? Not a bit. I'll happily shard five new primary legendaries to keep my signature weapon relevant. Do I mind a small, hard limit on the number of legacy items a character can advance? Perhaps as the end goal of a tough quest to earn the privilege? Again, I don't mind a bit. But I'm not going to grab my ankles at BOHICA, and ask if I can have another.