As a matter of fact, I have reliable stats on this question.
In shotgun vs laser duels, the shotgunner wins in 59% of the cases. That's ALMOST even.
The REAL weakness of the laser is against other weapons than the shotgun. E.g. against Uzi users, shotgunners win in 41% of the cases, while laser users just win in 30% of the cases. Against Electro, shotgun wins in 35% of the cases, but laser just in 19%.
So the shotgun certainly is NOT too weak. Stop spreading that myth. As a starting weapon, it is balanced just right. It's sure the worst of the "actual" weapons (that is, excluding laser, hook, porto), so every weapon you pick up is an upgrade for you. But it certainly is not useless, as these stats show. You'd be MUCH worse off with a laser.
In a way, the SG is comparable to UT's enforcer in this respect.
We need a "double shotgun" mode where you can hold one with each hand

1. Open Notepad
2. Paste: ÿþMSMSMS
3. Save
4. Open the file in Notepad again
You can vary the number of "MS", so you can clearly see it's MS which is causing it.