I think you are onto the actual causality -- McDonalds serves low quality burgers that have a certain taste that its core customers do actually like. When I fi

I think you are onto the actual causality -- McDonalds serves low quality burgers that have a certain taste that its core customers do actually like. When I first tasted an UmamiBurger the first thing I thought was "wow, this has the mouthfeel and intense flavor of a big mac, but it's way better". Replacing whatever meat blend is used with "Angus" is unlikely to improve the flavor -- who cares about uniformity and marbling in ground beef! Things like never serving unripe green tomatoes or wilted lettuce would go a long way, as would avoiding serving burgers that have been sitting around too long. I imagine that if prepared fresh (like Chipotle is) nearly anything from McDonalds would taste significantly better.