So if you're talking about Ethereum as a bad implementation of a good idea, you're weighing up reality against something that was a hypothetical from 1994 to 2014.
In any case, there's plenty really obviously wrong with the idea of immutable smart contracts. Legal code is a bad match for computer code; immutability means changes in circumstances can't be allowed for; immutability means you must code with zero bugs; the oracle problem (getting real-world data in and out of your smart contract) ...
"Dr. Strangelove" is the story of a smart contract going wrong, unstoppably, immune to human intervention.
Szabo's stuff is better than the reality - he does actually understand law as well as code, and at least early on he considered there was a role for human intervention - but it's still the sort of thing that's "interesting" rather than "a good idea".