Not necessarily true. Most all weapons are situational. For nightfalls/weekly heroics, it would depend on the burn. Let's say I am running a nightfall with arc damage, or course I enjoy using my fatebringer, but if it is a hive centric nightfall like the summoning pits or Omnighul, I usually use my my oversoul edict to shoot through knight shields. Then you would more or less want to use raid specific weapons for their respective raids due to the perks.