Again, I ask you for a cite. I linked you to the Betamax decision which established that the product must have substantial non-infringing uses to avoid contributory infringement. You acknowledged that this emulator does not. Why are you ignoring this?
And I did, you're just choosing to interpret it differently.
The Betamax decision requires that a product has substantial non-infringing uses to avoid contributory infringement. Emulators do. They're used all the time, from freestanding emulators such as MAME, to various smartphone ports.
An emulator, by itself, is entirely legal. It's copying functionality from one piece of hardware to another. The fact it can run rom images doesn't make it any more or less illegal. For an emulator to be useful, it has to be able to run the software for the platform its targeting, and running software from another platform is the accepted and primary use of emulators.
So the emulator code by itself, using nothing but homebrewed code reverse engineered from another platform, is perfectly legal. The fact you can download a rom off the internet, despite it's "intended" use for only being for images ripped off media you own, doesn't make it any less legal. It's potential for abuse doesn't mean it WILL be abused. Buying two Betamax players to pirate rented movies doesn't make Betamax illegal, but the availability of Betamax players does make it possible to do so.
Emulators are legal. Roms and other copyrighted works are illegal. Therefore, emulators distributed without any copyrighted materials are legal.
And a link.