Yes Massive, you are right ... the guns in The Division are not perfect right now and everyone tries to get the same "uber" weapons. But nerfing those and giving other guns more damage does not solve the problem. If you do this again and again, in the end you will have every weapon doing the same DPS. And you don't want this, cause it is boring.

So what's the solution to this problem?

Give the weapons useful procs, like some of the M1As have a chance to blind NPCs.

Examples:
SMGs could proc a group heal.
LMGs could force NPCs to take cover or proc a debuff.
Shotguns could proc a stun.
Assault rifles could proc a group buff.
Sniper rifles could (like some already do) proc a blind.

Now combine these procs with the gear sets.

If a tactician uses SMGs, the heal procs more often and with more power.
If a sentry uses sniper rifles, the proc happens more often and blinds for longer.
If the striker uses assault rifles or shotguns ... you get what I mean.

This way it will make sense for groups to specialize and use different guns ... as everyone will have a "real" role in the group.

Don't nerf the guns. Give them a meaning.