I don't think you'll get much disagreement there. That said, there's a legitimate rationale behind designing your processes such that even negligent behavior might be avoided. If you were to do some failure mode effect analysis, and the outcome of taking off on the wrong runway is near certain death for the passengers, then the FAA might be justified in instituting additional process controls no matter how small the probability of occurrence.
I understand your point, but I think that this is something that has, to my knowledge, never happened to a US commercial carrier before. This would indicate that rather than spending vast sums on technology - ground radars asked for in one post, RFID schemes in another - it might be more effective to simply remind pilots that they should take off on runways designated for commercial traffic. Of course the crew of 5191 has already accomplished that for everyone. No need to do much else, I'd argue, except keep the focus where it belongs, crew performance.
Who knows what was going on during the taxi, but there is just no reasonable excuse for doing this. As an example, there was a small cluster of incidents in the 90's where pilots were landing at the wrong airport. There were at least 2 incidents with commercial carriers. The publicity was bad enough, and I doubt the pilots involved escaped with their careers intact. Since then I've not heard of anything like that happening again. Certainly this incident will have similar corrective effect.