Dear WTS.
Let me try again as you seem to be having some difficulty .
The NW at Michigan ( there have been others AA and Delta) took off with an incorrect flap setting. To repeat your question ( rhetorical?) without the gratuitously offensive acronym- why would they do it? I don't kmow. I assume it was inadvertent, but they did. My sole point is that- would it not be better for everyone if aircraft were designed to inhibit roll where the flaps are incorrectly set as with my car which will not start unless it is in neutral. SSR ( the professional pilot) has understood and replied politely.
Best Wishes