You liar, someone will give it a 10.
Someone will. I expect more 9s and some 8s, though.
As troll-y as some of the people who really, really, don't like 3D World come off, they do represent the opinions of a certain segment of people disappointed that 3D World is not revolutionizing Mario like Galaxy and 64 before it and those people are likely to review games.
No online multiplayer, the inability to mention a second quest (if there is one), difficulty, coming within a week of more-powerful consoles, etc. If you fell off the fence a certain way, it probably would not be difficult to justify giving Mario a mediocre score.
Then again, everyone hated NSMBU and I found that game fun as hell, just saying what I think will happen. It's not paranoia or a persecution complex, mind you, I don't think anyone will be grading with biases or agendas that can not simply be boiled down "This person likes what they like."