>Your perspective on this is distorted.
You make an excellent point. The entire point of Tornado Cash is[0]:
"Tornado Cash is a cryptocurrency platform. It is a Cryptocurrency tumbler, a service that mixes potentially identifiable or "tainted" cryptocurrency funds with others, so as to obscure the trail back to the fund's original source."
From a legal standpoint, such functionality has few (if any) purposes other than to circumvent the law.
As such, preventing such activities is likely a societal good.
I expect you won't get a lot of love from some folks here, as they aren't interested in societal good. They seek license to do what they want whenever they want, without regard to the impact on the society in which they live or those they live alongside.
And in most cases, that's just fine. I strongly value liberty myself. I'm not as dogmatic as some, but I strongly believe that the only actions which should be proscribed are those that limit the liberty of others.
In order to maintain that liberty, it must needs be an ordered liberty that discourages activities that cause harm to others.
All that said, what governments decide is "criminal activity" is often arbitrary and unfairly/unevenly applied.
This creates distrust in the legal system, which Tornado Cash circumvents. Which is why not a few law-abiding folks (especially in the age of surveillance capitalism[1] want the capabilities (anonymization of financial transactions) offered by Tornado Cash.
What's more, the legal system in the US actually works pretty well, as compared with other nations around the world.
It's not the best, nor is it free of flaws, but it's definitely better than nothing.
This (how to make our ordered liberty as broad and as fair as possible) is a complicated and nuanced topic. I haven't done it justice in this comment.
While I do appreciate the value of a platform like Tornado Cash (how, and with who, I effect financial transactions shouldn't be of concern to anyone other than those involved in a particular transaction), it's pretty clear that without appropriate controls (AML/CFT regulations) enormous harm can be done. In fact, this episode shows that enormous harm was done in the absence of the implementation of those regulations.
Github will comply with the law when it is required of them.
They have a business to run.
[0] https://en.wikipedia.org/wiki/Tornado_Cash
[1] https://en.wikipedia.org/wiki/Surveillance_capitalism