Shared Stash logic

The point of the shared stash was to make it convenient for players to move items between characters.

It, however, prevents you from transferring any of the quest related items.

I can join an open game and go throw a Cube and Khalim’s Will, Horadric Staff, the Hell Forge Hammer, or any other of these stash locked items into a corner and then switch to a level 1 and grab said items but I can’t just use the Shared Stash to do the same thing?

I understand that the developers don’t want players get rushed (that’s a whole another topic) but they are also making it more difficult for individuals to power through the early game as well.

Khalim’s Will is arguably the best Level 1 leveling weapon in the game. The Cube has its uses on mules.

There is not a single item in the game that is player bound. What is the logic behind not allowing these items to be transferred through Shared Stash?