Doing quorum at the computer level would require synchronizing parallel computers, and unless that synchronization were to happen for each low level instruction, then it would have to be written into the software to take a vote at critical points. This is going to be greatly detrimental both to throughput and software complexity.

I guess you could implement the quorum at the CPU level... e.g. have redundant cores each with their own memory. But unless there was a need to protect against CPU cores themselves being unreliable, I don't see this making sense either.

At the end of the day, at some level, it will always come down to probabilities. "Software engineering principles" will never eliminate that.

There are a lot of seemingly high-level problems that are solved (ingeniously) in hardware with very simple, very low-level solutions.

My first employer out of Uni had an option for their primary product to use a NonStop for storage -- I think HP funded development, and I'm not sure we ever sold any licenses for it.