To be fair, a week is too short for most of the demographic for this game.
It's only up until this week that friends, family and people at work start to ask me questions about "the new Mario kart".
Then, when I tell them it's out next week, they all react the same: wow, next week already???
Don't forget we (the core Nintendo fan base) are a fairly small group of the total potential buyers.
Nintendo absolutely needs this week extra to build momentum and hype within a far bigger target audience.
But indeed, the waiting game for us is really frustrating