That is completely unrelated. It has nothing to do with him personally. The application itself, Tornado Cash, is still accessible and being used widely. The founder itself did not manage and facilitate cryptocurrency scams per se. He simply did not do crypto scams. You are taking a wrong understanding that he contributes directly to the cryptocurrency scams.
The actual problem is that cryptocurrency scams can happen even without Tornado Cash, there are many tools that those scammers can utilise to hide their footprint. Charging the developer obviously did not solve the actual problem.
Indeed as such, I do say he is not directly related to those things. The case do similar to any other application, any developer can build things that might conform to legal activity, and so does in a certain manner an illegal activity.
What I try to emphasise is that just because the mere developer is being charged due to his involvement in the project does not mean it will automatically reduce the amount of cryptocurrency scams. This point is what I tried to align because it seems OP got the wrong point of view. Cryptocurrency scam is enormous and varies, on the contrary, Tornado Cash is a minuscule thing.