No comment on epistemologies, but (as someone who regularly bakes cakes) I must object to your views on cake.

It would be quite a stretch, I think, to say that cakes may usefully be classified as "good" and "bad", or "tasty" and "not tasty". Individual preferences are one reason, of course. Regional/cultural/etc. preferences are another. What threshold of "acceptability" (for any meaning of the word) you accept for your cake is yet another. How many people are "most people" is yet another.

In many of these things, there are both gradations (which do not, themselves, threaten the good/bad distinction, only force it into a continuous variable instead of a binary one) and sharper categories of ways in which a cake may or may not be acceptable (which do). For instance, a cake may be "bad" by being inedible by nearly anyone (you mistook salt for sugar); it may be bad by being a bland, sugary superstimulus, good-tasting but lacking in interesting flavor (you ruined or omitted the more delicate flavor-granting ingredients); it may be bad by being unacceptably and avoidably unhealthy (many forms of buttercream tend toward this); it may be bad by failing to satisfy the criteria of its design (you set out to make a red velvet cake, but the result was merely a chocolate cake with buttercream frosting and red food coloring).

And that's not even getting into the quality of a recipe! One may make a cake by following either of two (or more) recipes that differ from each other far more than their versions of the finished product will! Recipes may differ by difficulty of execution; by difficulty of acquiring ingredients; by sensitivity to variation in conditions of preparation; and by other factors. And what is an "average person", anyway? Do we judge a recipe by how reliably it makes a "good" (see above) cake when followed by someone with little or no knowledge of baking? Or by an experienced, though non-professional, home baker? Does "average" refer to general intelligence and cognitive ability? Some of these criteria are less fair to the recipe than others, I think!