If you're not able to keep promises you shouldn't make them in the first place. The buck stops with you, period.
No pilot training was often used as an argument. But I think the problem was actually much more severe.
If Boeing would have designed a completely new plane (which they should have) they would have lost a decade to Airbus' offerings in their most important market.
That, in my opinion, was the real reason for that shoddy hack of a plane.
But if they'd been honest about the fix, required pilot training, maybe this problem would have been discovered in a less catastrophic way so it could have been fixed earlier. It wouldn't have been as cheap as they'd like, but they'd still have a foot in the door in that market and they'd have their reputation. Now they squandered everything.
The horrible thing is that this sentence could be applied to other Boeing products as well. The Delta IV springs to mind.
I don't know how you can look at this whole situation and think "yup, free market working as planned. Everything fine and normal!"
Besides, the reason we have regulations is because there are limits to the free market if we want to live in a sane society. Markets only find optimal solutions if everybody has perfect information, but in reality nobody has perfect information. You're free to choose between brands of honey, but it's expected that the government will ensure that no honey contains plutonium because 1) a consumer can't easily tell if it does and 2) it's assumed that everyone would avoid radioactive honey if they knew about it. Similarly, airlines are free to choose between aircraft, but it's assumed that none of them want an aircraft that will spontaneously and uncontrollably dive into the ground; it's the government's job to ensure that nobody sells such a plane.