McDonald's is still very much alive and well at Disney World. There is one stand at every park. Plus the full restaurants at Downtown Disney and by the All Stars.
I'm not a fan of McDonald's in the parks and I refuse to eat at them myself at Disney World. But, I'll take them in the parks having fries and nuggets available for kids who need familiar food for lunch or dinner over having those same kids having a meltdown because they are hungry and there's nothing they want to eat. A happy kid eating McDonald's fries is much better than a crying, whining, hungry one. McDonald's is just one food choice. If you don't want to eat there, you don't have to.