Actually I'm inclined to agree this is a fairly ineffective solution to a bigger problem. But that doesn't mean that anybody is demanding "preferential" treatment, or that they get it. Ladies waiting rooms, for example - rare though they are these days - provide a safe(r) place for women to wait where it's more difficult for men to harass them. Accessible parking spaces provide more space for mobility aids and reduced distance to facilities, so that disabled people can still get to the same things as non-disabled people even if they can't walk across a car park to get there. They don't aim to put anybody in a "better" position than when they started.