Abstracting the question to whether tumblers or cash or guns or whatever should be 100% legal or 100% illegal is too reductive to be useful for anything but rhetoric.
It’s when people take actions with intent and outcomes that the law gets interested. Those are what we should talk about.
Cash has lots of legitimate uses and some uses which I’m fine saying are illegal. Ditto with guns, even speech.
In this case the summaries at least sound like there was tons of evidence he was specifically designing and building features to make the service better for criminals, with the intent and outcome of facilitating criminal activity. Behaviors, as the prosecutor said.