I agree that right now the legal system still applies.
The problem is that lots of smart contract enthusiasts embrace them for the same reason they embrace crypto currency: they see it as a way to avoid government institutions that they do not want to have to work with or trust. In fact they want the entire contract to be trustless: agree to the terms, implement them in code, and and since the rest is automated you don't have to trust that the other party won't follow through.
I don't see how that can actually work in an automated fashion. Whether it's traditional government or some other legal system or analog, you need a resolution layer above contract layer, but at that point you've lost a lot if what enthusiasts want in smart contracts.