Why? Only if we up the difficulty to a light level we can't reach, like with the raids. I already speed through strikes with a team of random in an average of 8 minutes, 5 for Psion players. Hell we smashed omnigul so fast the other day I was still clearing the starting knights and didn't even get to shoot her so I didn't even get blue weapon drops. Lol imagine with 6.
I think it'd be cool but is there enough space and enemies to justify it? It might be too hectic. You wouldn't really be able to separate much from your group so explosions would be team killers.
I'm down for fireteams of six being able to do all activities in the game together. Including Rumble. For Rumble, just disable quest and bounty progression 😉