The question is what level of prevention is considered enough. Wasabi does more than Tornado Cash, but banks do WAY more. Yet even the ING director is being criminally prosecuted for not doing enough to prevent money laundering. That's after ING paid a massive settlement.

Also note that Tornado Cash arguably did all it could given the constraints of a smart contract - i.e. nothing. A prosecutor could argue that a wasabi coordinator should not only screen the UTXO's for a round but also perform full KYC on each owner. That's completely unreasonable in my opinion, but my opinion doesn't matter...