By killing all the trash mobs I've aquire more legendry engrams than through any other method. Also with a full group killing trash mobs you can complete the strike faster than having to wait for the guy that screws up and constantly dies trying to run through. Your opinion is not wrong and neither is mine. It's like cheesing unless I'm soloing the night fall I feel no reason to do it however there are countless others that always do it. Doesn't make them wrong. Play the game the way that makes you happy and quit telling people they play wrong.