This has probably been the cool thing to do since everyone's completed the same half-dozen maps a few dozen times and really can't be bothered with the trash anymore, since everything everywhere drops equal chance at loot, but only completion gets you a guaranteed reward and some rep and marks. (Though patrols/events are a much faster way to get rep/marks.) If you don't wanna keep up, you should probably only run with a fireteam of people who you know what to play at the same pace. Or just I dunno, get booted for not keeping up and helping out with the actual events thanks to your OCD insistence on clearing trash that doesn't actually follow you through to the main combat areas. *shrug*