At some point your designs start breaking into envelopes where the machine cannot be considered safe once the automated systems fail, making your pilot/highly trained human being powerless in the face of catastrophic system failure.
An uncontrollable tool is not a tool, but a coffin waiting to happen. I don't think any type of "routine" transit system should be designed in a manner such that it so thoroughly overwhelms a human crew's workload that it should be so dependent on automation that it cannot be certified otherwise.
To reword: if it can't be safely flown with the computers off, it probably should not be a design we allow for people transport. Markets be damned. When your margins include human lives lost, economy needs to stop being your primary optimization. Dollars should only be important after you stop being a corpse factory.