Surely you're not arguing that popularity/profitability equates to quality? If so, McDonalds represents the best hamburger and fries in human history.

There are more dimensions than popular appeal.

>There are more dimensions than popular appeal.

In the context of a consumer product, not really. Everything is always a tradeoff to optimize for multiple factors. Mcdonalds may not be the highest quality, but they've sold billions of hamburgers for a reason. Their product is what the market wants, with enough acceptable tradeoffs to operate at a scale that fulfills demand.

tl;dr: The customer is always right.

What is quality?

Short answer: Usually not the lowest common denominator, by definition.

Longer answer: Read Zen and the Art of Motorcycle Maintenance