The iPad also comes in 32 and 64GB models so the consumer has a choice of more capacity. It is also possible that the Nexus scores went up before there was a 32GB version (it launched with a choice of 8 or 16GB)
But gdgt didn't give the iPad an 8.0 on storage. That is an average of 10 critic reviews from Engadget, PC Mag, TechCrunch, CNET, Ars Technica, Macworld, SlashGear, Pocket-Lint, The Telegraph, and Trusted Reviews
So those are the correct websites to ask.
Think too, that the iPad has a built-in cloud based account that holds data. To get that on the Nexus you had to add an app that while included now isn't as well advertised. i.e. Google Drive.
The problem I have is the price. There is not $200+ difference in features to warrant the price. The mini which people said was too high priced for it's size and features, also, now people rave about. I get that people who are stuck with iTunes stuff, most do not or choose not to, know how to move their stuff over to Android. I just wish both sides, like politics...lol, would be more open minded.