But that isn't a good comparison for this case as what he did was not illegal. Unlike hitting people with steel pipes.
Our pipe-wielding example will just find another victim without a helmet. You can always find something a victim could have done differently, the only common thread is the perpetrator.
Also legality isn't a proxy for morality. Slavery was illegal. Some societies allowed cannibalism. What Soros did had a human cost and the fact someone else might have done the same financial alchemy had he not doesn't excuse it.
As for the pipe and helmet example. The laws and ways of upholding them are the metaphorical helmet that we put on to protect ourselves against pipe wielders.
The perpetrator will do what it wants to do, we can protect ourselves with laws, law enforcement, education or physical armour. Or do you expect the pipe wielder to stop because they were told what they are doing is bad or amoral?