Royal uses all of their qualifiers (Military, police, fire, senior and resident) as a way to drive sales and not because they are rewarding those in that specific target group.
Some or all of those discounts may appear on selected sailings where they still have cabins to sell. By offering those discounts they can reduce the cabin price to a limited number of people and do not have to worry about large numbers of guests calling in for price drops which may happen if they lowered the price across the board for everyone.