True, but shouldn't that have been a feature in the base game? Maybe it was to soon. perhaps warmind, where there was a mass demand for the weapon slot changes. They waited to the launch of the dlc to make numerous changes that bloat the content of the dlc

Yes but bungie thought having two primaries and a heavy was a good idea since people complained about special weapons in d1. However, when bungie removes special weapons, the community asked for them back. Bungie made a mistake but it was one they eventually corrected

Bungie only listend to the PvP players rather than the pve players once again. The problem with special was that the ammo was so readily available which is also a problem were experiencing again with shotguns right now. Moving the weapons to the same slot as rocket launches or swords was a move only bungie could pull off