each Macdonalds has its own prices it sets to deal with rent and other costs of location. Also the KFC punchbowl wont only target people leaving in punchbowl but the surrounding areas such as lakemba, wiley park, bankstown, etc who also have a decent muslim population. Also their is no proof the owner is muslim, but merely trying to cash in on business. Much like the punchbowl macdonalds owner who I know is not muslim, but operating halal macdonalds (but it does sell bacon aswell).
Each franchisee has its own agreement with the franchisor so their is no hard and fast rule about it. Sorry but business studies year 12 way far from the real world.