The following review scores come from this week's issue of Famitsu:
Mario Kart 8 Deluxe (NSW) – 9/9/9/8 [35/40]
Dragon Ball Heroes: Ultimate Mission X (3DS) – 8/8/7/8 [31/40]
Wonder Boy: The Dragon’s Trap (NSW / PS4) – 7/7/7/7 [28/40]
MK 8 Wii U had a 37/40 score, so Wii U > Switch version!
The logical guess would be that they reviewed it a bit lower since it doesn't add a whole lot to the game. (no new non-battle tracks for example).
Goodness, why is the WB remake so low scoring? Everyone else seems to enjoy it...
That's not really a low scoring ( well considering its Famitsu I guess it is since the overscore things sometimes). Also some of the reviews that came out today for the game are kinda similar to this: "Great game with minor problems, 7/10". I guess its because its a short game/a remake with not many new things so it tends to get a lower score.