I think you missed the implied point. Numbers are one of a number of causal factors in what makes something fun.
They're the *only* causal factor, depending on how you look at it. All things exist in a measurable state. Colors exist on a scale that can be represented numerically, animation times and recharges are counted in seconds, resources and meters come in and are replenished in a finite quantities, etc.
You could really just boil that down and say that fun is logically representable. As in, you don't even need numbers, what causes people to experience "fun" can be narrowed down to a fundamentally knowable state that one can simply measure with their senses. You can even condition people into *being* part of the knowable state, hence my mention of masochism.
"Fun trumps all" as a response to numbers is not only a gross simplification, and an empty platitude... It's outright fallacious reasoning and creates a broken form of circular logic, which is utterly useless when trying to make informed decisions. You do realize that when you're creating a game you have to make objective determinations on things like fun, right? You do realize failing to do this is more or less paramount to creating a giant game of Calvin Ball, correct?
Fun trumps logic.
Ok, ok, so MY fun trumps YOUR numbers.