1. Add MCAS system to artificially make airplane fly as if it were a different airplane.
2. Drive MCAS with only one AOA sensor.
3. Don't tell MCAS to look for (or even think about) bad AOA data or AOA disagreements.
4. Equip airplane with two AOA sensors as usual, but make the AOA disagree warning light a "value added option" that customers have to pay extra for.
5. Don't actually bother to tell pilots that they don't have AOA disagree warning lights.
6. Don't bother to tell pilots that MCAS exists at all.
7. Don't test MCAS subsystem to see what it actually does with bad AOA data.
8. Give MCAS a ridiculous amount of control authority, operating cumulatively over repeated applications to exceed what the pilot can manually override.
Now, exactly what items on this list are the responsibility of non-union labor in a South Carolina assembly plant, or whatever other mistuned horn you're tooting? Once again, in the absence of gross engineering malpractice, a broken AOA sensor is no big deal.