But it is deeply concerning. Whether or not you like crypto, you should not be supporting this if you are a researcher, academic, technologist, cryptographer, or privacy advocate. The code for Tornado Cash is a series of cryptographic and mathematical functions that can be repurposed for a variety of applications unrelated to privatizing user wallets.
Having it open source and accessible is a net benefit for the entire world.
EDIT: A comparison would be that US decides to sanction the open Matrix protocol and any developer that has contributed to it, as it can facilitate end-to-end encrypted terrorist communication.