Eh, Goodreads has always suffered from the same problem that plagues every other review system which uses "score out of X" ranking. Humans just aren't very good at ranking things on a normal distribution, so you invariably end up with every item (books in this case) being ranked somewhere in the 3.5-4.5 range (since Goodreads is out of 5). For IMDB the rankings all hover around 8ish. When in reality the average book…
The non-industry people reviewing Zelda have 4 options, 7/10, 8/10, 9/10, 10/10.
A 7/10 means the game was bad and you had a hard time finishing it, and won't be playing again.
8/10 means the game was also bad, but you had fun for a few minutes/hours.
9/10 means the game meet minimum expectations.
10/10 means you enjoyed the game, but there were countless flaws that took away from enjoying the game.
10/10 Greatest game of all time means, the game was above average.
Now, this same system applied outside Nintendo's curve, you knock these numbers down 2.
Its incredibly hard to figure out if a Nintendo game is good, if you treat them like other companies. Even Nintendo believes this and will yank early access/ads/etc... from gaming websites if you don't comply with the Nintendo curve.