Because you are probably a basement dwelling cuck.
The thing is the hollow death threats are just an excuse, the real goal is the viewpoints of the people you despise and the tech weenies despise being suppressed, and anyone holding them becoming a digital unperson.
Hollow death threats? Maybe you don't know much about stochastic terrorism. But this kind of environment is what happens to cause radicalization at which point in time people break off and actually engage in the violence.
Take 4chan and the Christchurch shootings. People engaged in this type of violent rhetoric at length. Many people. And yeah, most of those threats are hollow. But then one of them decides that it's time to actually do something and next thing you know 50 people are dead.
Keep in mind that the whole point here, the very thing you're demanding, is that Amazon is forced to support the propagation of these "hollow threats" that very recently culminated in a riot that killed 5 people.
Do you think all conservatives have been kicked off Twitter and Facebook?