I view most primary weapons as minion-killers. Not the best when tackling bosses or in PvP. Granted AR are over powered (there's very little argument to the contrary) in PvP, primaries in general don't seem to be intended for laying waste to gold-health or Crucible opponents. That's the job of the special and heavy weapons. My snipers are my go-to for environmental heavy-hitters because they do 5-10 times the damage as my hand cannon or scout rifles. In the Crucible I choose a secondary based on the map, because each represents a different 1-hit kill criteria. That's what they are supposed to do. But I just don't see primary weapons, exotic or otherwise, being equal in the department of pure force. They are less situational, more balanced in their use. You don't need to be 5 feet or less to kill, or 10 yards or more to aim effectively. They take longer to kill something that isn't low quality, but their threat ranges and situations of usefulness are so much broader.