I don't know what's with the hate on Granny Smith. I love Granny Smith apples. They are especially good for making Waldorf salad. They are also my favorite to eat with honey at new years. They have a nice crispy texture and are delightfully tangy.
I pair it with some cheddar cheese.
Another good pairing with cheddar cheese is Mcintosh. When they're in season, they're great.
Lately I haven't been able to find mcintosh apples in the store (or if I did, they're mushy and gross). I suspect that's the case with a lot of these apples. The Mcintosh apples I got in Connecticut were great, but here in Texas they are trash.
However, you mentioned the pairing and combinational use of the GS, which is where it shines. Granny Smith is meant to be dipped, diced, baked, smothered, cheesed, etc. The GS goes way up in rankings, when you pair it with other foods.
I think that's why GS is low on the rankings. It's probably getting a bit harsh of a review on that site, I grant you, but again I don't think it holds up as a standalone apple quite the same as others.