On the extreme lets say that Amazon stock goes to $0, it would reduce the wealth of the world by about $1 trillion in stock valuation. That means that $1 trillion disappears from people's accounts (with ~$100 billion disappearing from Bezos' account). This would be wealth destruction no different from simultaneously reaching into every person's wallet and removing some amount of cash and burning it.
The whole "[corp] is not a person so [immoral act] is okay" is not productive.
Unrealised profits are very much different than physical cash.
Some would say that in the first case it's morally wrong to steal my cash, whereas in the latter case I consented to the risk of my ticket losing when I purchased it; and therefore performing a lottery draw is not an immoral act.
You still own your shares. You were not robbed, your gamble did not pay off.
Also, for this to happen, Amazon would have to be very very very bad at doing its job, which is to sell products for a profit. A company that is that bad at doing its one job has no god-given right to remain liquid.