They've ranked Granny Smith as "Not worth eating" so right off the bat I can tell you the rating system is junk.
It loses the most points on its "density." Can't say I've ever eaten a granny smith and thought "I enjoy this taste, but I sure wish I could change the density."
It's just like any kind of snobbery. If you want to be a connoisseur, it's practically obligatory to detest all the popular options. Because you (i.e. this website) are the expert and the commoners must be tasteless and wrong!
I love the sourness and the texture. Too many popular apples are just "mealy" texture. I've tried some of the other tart or sour apples and they are just not as good.
Matters of taste are subjective, but subjective does not mean "all in your mind." There is such a thing as good music, good conversation, etc. There are no objective tests, but that's not the same as non existent.
Good tastes exists. OP just has bad taste (in apples).
I think this attempts to rank apples based on how people would rank them on average. I think it's good for that. Not a lot of people like Granny Smith apples. Maybe I would not say it is not worth eating, but I wouldn't suggest it unless you wanted something different?
I was waiting to see this comment. These two are very popular in US markets but are world's apart in the opposite direction. Gala are straight mush. TBF they do caveat: "You MUST buy Gala’s that are grown where it is currently Autumn... for an off-season Gala may be nothing more than a six-month old, previously frozen, grain silo in a fruit jacket." Which is 75% of the time...
Granny Smith is a trash tier Apple. The skin is inedible and it is absurdly sour. It's only edible if you peel the skin, cut it up, ...and bake it in something else. Alternatively peel the skin, and dip it into something such as peanut butter. By itself, it's trash tier.
I don't like them by themselves, but I love them with other food. For example, with a nice nutty cheese and maybe some fig jam. The sourness can be perfect with a sweet counterpart.
It loses the most points on its "density." Can't say I've ever eaten a granny smith and thought "I enjoy this taste, but I sure wish I could change the density."