Considering it has the most content of all Mario Kart games (and kart racers in general?) this is unfortunate. I still applaud Nintendo for taking a solid approach to DLC in Mario Kart 8 and we can only hope that there's more after the second DLC pack, or that the second DLC pack will be enough to round out the experience.This is one of Mario Kart 8's biggest flaws and a shame really because it's a great game if only it had tons of content.
If you compare the DLC tracks with the standard tracks, you'll notice there's little variation in the standard tracks and only few tracks truly take advantage of anti-gravity. That's Mario Kart 8's biggest problem. Some of the DLC tracks already have been excellent, but there's laziness to them as well (e.g. SNES Rainbow Road).