Trouble is, when you start with a range of quality, the achievement of consistency usually results in a product at the low end of the range because the better outlyers have been eliminated.
One possible reason quality has suffered in chains is that they have been relentless in the search for fool-proof product so that they can hire people capable of producing little else and pay them as little as possible. Does anyone think the nice kid behind the McD’s counter whose only English consists (if you’re lucky) of "big Mac" and "diet Coke" actually knows how to COOK? Of course not, but he she might have to to produce good food. To follow the chains "recipe for production of cow-based (or, as rumor would have it, kangaroo-based) hocky pucks" though, they don’t.