Law is law, code is code. They're two very different things. Code can't prevent someone from using violence to force you to overturn a smart contract's decision. The law can because it's enforced by the state. You could certainly choose to build a system of law that uses code, but code by itself cannot substitute for law.
> only interpretable by lawyers who charge $600/hr.
What do you think the going hourly rate would be for software engineers capable of writing bug-free smart contracts? If adoption takes off I'd bet that it will look a lot like the hourly rate of a good lawyer, or even exceed a lawyer's hourly rate given the impossibility of an appeal if the smart contract is poorly coded.
Also lawyers don't interpret contracts. They draft them and advocate on behalf of their clients in disputes. Judges interpret contracts, and are available as a public service paid for by taxes.