Some people really aren't seeing the bigger picture.
There are 3 reasons why Shotguns are the most used weapons in Destiny:
1. Blink + Shotgun is stupid easy to pull off with virtually no risk involved.
2. Shotguns are easy to use and can kill from ridiculous ranges.
3. The map design largely favors them with excessive corners and chokepoints.
The last part is also one reason why Autos will always be ahead of the semi-auto weapons. They have more DPS in CQB and they're also easier to fire there.
Removing special ammo off of spawn IS NOT going to fix the situation. Limiting special ammo makes the game worse because it makes Supers more powerful. When Supers are more powerful, players can play more defensively while they wait for them to recharge. Special ammo is a constant counter to supers, and less of them means that balance is tilted. Lowering the Super meter regeneration could solve that problem, but then everyone will just start using Thorn.
More rockets is not the solution for that part either. At all. Nobody should have more than 2 rockets and a machine gun shouldn't have more than 2-3 reloads. If more heavy ammo is going to be added to the game, their spawn time needs to be reduced to once per match. You can't have heavy coming up 3 times and then give people enough to get 15 kills with.
Data is meaningless if you can't comphrehend why things are happening. Most of Bungie's changes to the Crucible show me that they don't really understand their multiplayer.
If they want to limit Shotgun usage, they have to nerf Blink, nerf Shotgun ranges, and redesign all the maps so that there are few optimal places for Shotgun usage. Alternatively, if they rebuff Fusion Rifles, those will replace Shotguns as the flavor of the month. After all, Crucible is all about using the most broken guns to get easy kills and right now it's Felwinter's Lie + Blink.