How could this happen? Why? Poor Lieutenant Hot_DAWG_69, you were so brave, so valiant! Why has Bungie taken you from us?
Well, according to Bungie designer Tyson Green, things have changed just too much. "The way you earn experience has been adjusted up and down a bunch of times. Items have been added and removed. New features toggled," Green wrote in a Bungie news post. "Although there's no single monumental change, the sum of the tweaks leaves characters from the Beta Build in strange shape that would be confusing at best, broken at worst."
Fair enough, we suppose. If nothing else, think of this as an opportunity to create your own Destiny lore. Your previous Guardian has fallen. Avenge them on September 9.