If you follow that trail far enough it's whoever designed cryptocurrency, right? Because banks can and do reverse transactions as last resort.
Banks can't reverse wire transfers. Unless there is some super-level intervention that is very rarely used. But they can trace where it went.
No, because this is explicitly the design of Bitcoin. If you give me a foo machine but it makes a bar, that's your fault. If you give me a foo machine and the foo hurts me, that's my fault.