First: Some exotics serve a certain purpose. Icebreaker, Mida, Bones of Eao, etc. Lightlevel doesn't matter in the slightest if they can help mastering special situations. It's just plain dumb to deny them just because they're "old". Second: If a weapon is better, it'll be used. Why should someone use shitty 200+ guns when he has better 170 guns they worked for? It's not like lightlevel matter in the normal crucible. Example: I've done over 100 strikes and put ober 100 motes into my Hopscotch, so I'll never going to put it down just because Bungie decided to make it obsolete after just a few weeks. So I keep using it, just like my Messenger/BTRD/Felwinter/Partycrasher/Benevolence. And for IB and Trials...well, I can still use my new guns like Hwaksaw, Apple of Discord, Conspirac Theory, 1000yard Stare, etc.