The argument that private transactions are only for people with something to hide is one that we should be very careful with.

The same could be said about projects like Tor, which we know for certain is used for all sorts of illegal activities, and really just about any use of cryptography use outside of big tech and systems with law enforcement access. It is exactly the same as the argument that all chat and email providers that cannot intercept and store plaintext data should be outlawed.

Private chats and private value transfers are used by criminals, there's no question about it. We should think of the children. But the slope is slippery and the question is where to draw the line and what type of society we want to live in. To someone who valued abolishing export mode ciphers and key escrow schemes, the Overton window has really shifted on this.