Yes, which is why most people do not run Tor exit nodes because it’s inherently riskier to have your equipment directly involved in legal activity. Tor is actually safer than this since the traffic is encrypted so a node operator can quite confidently say they don’t know the contents. Some of the charges in this case will depend on whether these developers were in fact similarly unaware of who their heaviest users were. That doesn’t help with charges related to not following KYC, of course, because unlike an IP network financial services are fairly heavily regulated.
Your belief expressed in #2 is at odds with the charges specifically saying he profited from money laundering activity. We’ll see when that goes to court exactly what that meant and whether there’s evidence suggesting that he knew where those fees were coming from.
The developers deployed the Tornado Cash code, and subsequently, had no control over it. They did control one of the front-ends to it, and they instituted blocking of transactions originating from hacks in that front-end. But criminals were free to use any front-end to access the deployed code, and there was no way for the developers to stop that.
In any case, what is being criticized in this particular thread is OFAC prohibiting all Americans from using Tornado Cash code. This is unprecedented, and clearly outside OFAC's statutory powers to sanction "entities".
Despite the US Treasury's claims, Tornado Cash is not in any way an entity, as it is not controlled by any party. It is simply code, running autonomously on a massively distributed blockchain. When someone uses it, they are using zero knowledge proofs to encrypt their transactions. The fact that this act of encryption adds their activity to the same anonymity pool as criminal activity is no more an argument for banning this encryption protocol as it is for banning any other encryption protocol.
Again, the problem is not the code but the running service. If you are involved in processing a transaction, you are required to follow applicable laws and risk consequences if you don’t. The technical details might explain how you got involved but they don’t remove the legal requirement.
Your belief expressed in #2 is at odds with the charges specifically saying he profited from money laundering activity. We’ll see when that goes to court exactly what that meant and whether there’s evidence suggesting that he knew where those fees were coming from.