That's not true, and we'd get to a much, much worse place if we relied on that. The industry put the current system in place because it could see that airlines would make gruesome compromises if consumer choice was the only thing driving safety.

What do you mean "if", anyone can choose what plane to fly on anytime.

Many airlines allow same day changes. If everyone scheduled on a Max reschedules for alternative flights consistently, they'll get the message soon enough. Refusing to board a Boeing plane at all is perfectly reasonable at this stage.