Plus, when it comes to the Egyptian dead, in a weird way, we are actually doing them something of a favor by preserving them for even longer. A modern digital photo of a death mask is going to last a lot longer than the death mask itself, especially if it has already decayed past any hope of preservation.
Many ancient cultures placed great import not only on how the physical remains were treated but how the person was remembered. There are cultures that placed both cultural and spiritual value on how well the deceased was known to the world.
Archaeologists who find the forgotten or little remembered dead bring them back and make them immortal in a way that they may not have understood, but probably would appreciate.