McDonalds has moved from the place middle class people like to go on occasion, to the regular staple of the diet of the lower proles - and the very worst element of them as that. The problem with the lower proles is that they only buy the dollar menu Items and are extremely slow, stupid, and disruptive to the ordering process and the environment in the restaurants. U could not pay me to take my family to many of the McDonald's in Downtown Chicago. Filthy, smelly bumbs everywhere and misbehaving "kids" gyrating, yelling, potentially fights breaking out. That is the reputation, it went too ghetto for the Middle class.
Get a decent tasting product, simplify menu, clean up the trashed out stores, service workers that do not threaten to punch you in the face and bust open your eyeball (as recently happened in Chicago) and get the police to remove loitering bums and "teens". That is a start. I think they can fix the chain, but its going to take work.