That ad makes fun of all mascot kart racing games, because Blur is using Gran Turismo style cars in a Kart racing environment. Mario Kart is the TOP game in that genre. I believe Blur has to differentiate itself by coming off a bit edgy and bad boy in its image, because of what it is.
At its heart, Blur IS a Kart racing game... just with different vehicles, so it is taking aim at those.