Security wait times hurt an airline’s business for short haul flights. Having to get to the airport early means that total travel time can take as long or longer than driving. In the Northeast for instance Amtrak has taken a lot of business away from the airline shuttle routes between Boston and New York and between New York and DC just because of the need to turn up at the airport earlier.
So if airlines can convince you that total travel time is less than you think — a ‘security wait time guarantee’ — you may be more inclined to buy tickets for those flights.