Who is the arbiter of bad UX? Everyone can agree on rotten fruit, what is a rotten user interface? Everything I've learned about UX is that a spreadsheet will

Who is the arbiter of bad UX? Everyone can agree on rotten fruit, what is a rotten user interface? Everything I've learned about UX is that a spreadsheet will solve tons of problems that it's the worst interface for. Yet that is what people often want.