Here is how I have come to accept this crushing blow to destiny: Bungie admitted they were a little unsure of how to do this stuff, or what they were even making. So maybe they're removing these weapons from being improved because they either dont know how to bring them in line with their decided meta, or dont want to change people's favorite guns so they fit in their plan. NOW What will destroy this mindset is if they do it again in the next dlc -.-'