Not the actual damage is dcreased, but the damage range. Sure, you have a higher rate of fire, but now you're most likely to be doing 5-6 hit kills. If you do the Time to Kill calculation on that (d(s-1) Where d is the delay between shots and s is the number of shots to kill), you'll see that you only just tie in TTK with the assault rifles. You may say that the Skorpion with Rapid Fire is easy to use, but I'd honestly rather use an MTAR and get 3 shot kills out to medium range if I'm gonna be getting 6 shot kills within the original 4 hit kill range of the Skorpion. However, I won't lie about this. Up close there's nothing that can match the Skorpions performance, besides maybe a Shotgun's or Sniper Rifle's one hit kill.
I love Scavanger for this very reason, and fast mag. You can run around dropping people with an EVO with rapid fire, just picking up the ammo and reloading after each burst as you go.
Do you find the range on it to be too good? I'm not crying for a nerf here, but I was very impressed with the range on it for what it is. It shoots rediculously fast.
The range for SMG's isn't meant to be Great, but I think the range is still pretty reasonable without being ridiculous. Keep in mind Long Barrel attachment is available for most SMG's as well I believe.
They need to decrease something on these guns. RoF especially since there is something to increase it. ARs don't have it.