You're right, Harry, Boeing should have told the crews. "If you're out doing flaps up stalls in your MAX, you will get an intervention from MCAS. Also, if you get a continuous stick shaker on take off rotation & are stupid enough to accelerate, clean up the flaps, & try to continue the flight with the stick shaker, you MAY get a repeated intervention from MCAS 'cause it thinks the airplane is stalling".
The second sentence here is only true if Boeing had realised that this could be the outcome of a single AOA source failure. If they had that knowledge and did nothing about it, then the courts will no doubt take that into account in due course because the failure to communicate it or manage the risk would indeed be seen as cynical. Please don't construe this as Boeing bashing - that would be as unhelpful as trying to shift responsibility to the perceived shortcomings of the two operators concerned. Play the ball rather than the man.
Regardless of what manufacturer or operator is involved, the question for me is whether the fault tree analysis (or whatever process was used) and the subsequent sentencing of risk regarding 'system X' during its design and checkout provided sufficient evidence to the regulator that system X was safe to be fielded. And IF the regulator falls into the trap of regulatory capture (still to be determined...) or does not have the necessary resources to satisfy itself that the manufacturer's claims are accurate, then the regulator could and should be held to account. In a safety-critical environment it should never be possible for a manufacturer in any country to mark its own homework.
If you would like an example of how this situation can occur anywhere, take a look at the airworthiness failure that killed 14 UK servicemen in Afghanistan in 2006 - you can read the lawyer's analysis of the process failings
here