Amazon currently sells fake fuses that have probably already killed people.

Amazon cares just slightly more about breaking the law then they about killing people.

https://www.youtube.com/watch?v=B90_SNNbcoU

That's because criminal prosecution and product tort liability are not meaningful deterrents.

Patent litigation is a different thing entirely. The burden of proof is lower, and the payouts are higher.

To put things in perspective, Apple, Amazon, etc., have lost patent lawsuits worth hundreds of millions over trivial aspects of their devices that are just tiny parts out of thousands compromising the phone/tablet/whatever.