The behaviour in question isn't simply producing retro games. It is producing something unique and interesting that their competitors are not offering. It is an edge.

If their competitors copycat McDonalds' marketing, they totally didn't get that message, because by the time they clone it, the uniqueness McDonalds demonstrated does not apply to them - they've made a copy, or even a shadow of what came moments before. The edge McDonalds had is their cliff to behold unless they find something unique to counter with.