Do you have the funds to mount a reasonable defense if you were to be prosecuted? Would a negative outcome significantly impact your life?
If you can’t afford to fight it don’t risk it
“The defendant installed software that they knew could be used to store illegal materials, proceeded to profit off it, and did not put any protections in place to try to limit this”
For some judges that’s all they’d need to hear. Amazon have lawyers and essentially an endless budget, processes and teams to defend their position and support law enforcement, they have no trouble defending themselves, but an individual could find themselves in a really tough position.
This otherwise sounds like worrying that you'll be charged with armed robbery because the robbers threw their gun onto your lawn while escaping the cops. Yeah, sure, that could happen, but only through a series of factual misunderstandings about who did what, not because you actually committed a crime.
Professional storage providers have legal departments that very carefully design systems in a way to avoid any responsibility. Also, those are limited liability companies and companies can't go to jail. As a private individual, I'd never offer to store anyone's data.
Possibly relevant to your question.
It's a very interesting question. If it ever happens. So let's freeze it for now. I mean if they use the funds to develop the company, instead of buying Ferraris and mansions.