Oh, it is EASY to kill off McD. 
Sadly, nobody does it. 
Simply create a salad bar like Sweet Tomatoes, using LOCAL PRODUCE, have decent coffee and above all, have a play area like MCD in a glassed area, cleaned 2x a day (night and after lunch), combined with a kid's toy (decent one, not the Chinese junk that McD and others have). 
THis would destroy MCD quickly.