Wow this is an interesting subject-- DEAD PEOPLES REMNANTS!
I agree with liljp wholeheartedly about a few of the things he has said. My only question to him and to any one else sporting similar opinions is have you ever lost someone very dear to you (parent? sibling? son/daughter? dog?)? Now by NO means am I trying to call you naive or mean or anything...I'm just saying I'd be ridiculously pissed off if someone dug up someone who died in my family.
When you lose someone, it hurts. I understand it's nothing more than a decomposing/rotting corpse, but the emotional value triggered when walking by the grave of someone you knew dearly is priceless. Knowing that someone dug up your friends' corpse, threw it in a garbage crate, and is using the plot for someone new would be grounds for torture in my book. Like you, I don't believe there's anything sacred or spiritual about a corpse...to me it's all about respect for peoples memories.
To answer your question plainly: Yes. *I personally wouldn't group a pet with the others you mentioned; I guess some people do though*
Hypothetically speaking, I would be angry too. Not because I think humanity has lost all respect because some rotting corpses were dug up, but because someone provided me a product that I spent thousands of dollars on, and then failed to come through with that product. I would be angry that I was the victim of a crime, that crime being stealing. I would be angry they didn't keep up their end of the bargain. I wouldn't be angry specifically because a corpse was dug up, or have some moral conviction that corpses should be treated as living individuals.
I wouldn't be angry because someone stole my good memories with that person...because they didn't. The memory of my sibling being lowered into the ground is one of the worst memories I have. I'd pay someone to take it away from me. The good memories are in my head. The good memories are triggered by pictures, videos, ideas, thoughts.
If someone dug up a grave I paid for -- a legitimate contract or understanding was made that the product I paid for would remain there -- and I come to find out that this contract was blatantly broken and my money stolen...that would be the source of anger. Not some notion that it's immoral to dig up rotting organic matter.