"if he has to do it often enough, maybe he'll quit."
How is making someone with some decency quit a valuable objective, when he will only be replaced with someone with no decency?
How is making someone with some decency quit a valuable objective, when he will only be replaced with someone with no decency?
Let's supposed eventually that position is filled by "someone with no decency." Then passengers getting screened become more and more annoyed and outraged, complaints rise, and potentially leading to change.
Now, that change might be to no longer have opt-out. But in either case, the possible course of events is likely not as simple as what you outlined.
While I agree that they'll be reluctant to raise prices, the damage of being represented as the airline that refused to "contribute to public safety" would be worse.