There are some very cool things about running a kart. Let me list the ones I thought were very cool.
1. You go fast. Nothing like flying 1/4" off the ground (or have your kart seat scrape the ground!) at over 80mph through the cones. There is hardly anything at all in the door slammer world that comes close to this in terms of cornering (near 3Gs), braking, or acceleration. And transitions. Holy crap it can happen fast. You spend most of the run playing catch up... and I like that. I hate waiting for the next corner in a slow car.
2. Visceral. You can see the tires, the slip angles. You feel everything. Wind. Noise. Errant cones in your lap. There is no closer way to be one with the machine.
3. Track days. Kart tracks are awesome and a great value (sadly we have lost the best one, Moran). Most kart days are from $20-30 and you can run until you are too tired to run anymore. And you will learn a lot.
4. You won't complain if the course designer makes the course too tight for the Vette.
5. Easy to haul. Throw it in the van or truck and get a small trailer. I used to haul my kart behind my 4 cyl Honda.
6. Easy to repair. Like being able to work on a lawnmower. Rebuilds are easy. Simple stuff.
7. Cheap to repair. Most parts are silly cheap compared to cars. New wheels for $30. Steering link for $12. Etc.
8. Tires are cheap. Less than $200 a set and you can mount them at home.
DOWNSIDES-
1. Noisier and dirtier than most street cars.
2. Some people don't like karts and will transfer that to you. They are few, but they think that karts should not be allowed in SCCA (and some dislike that you are faster than them, in your "toy.")
3. You will need to maintain the kart more than most cars. Easy and simple, but you have to keep fasteners tight, possibly change gears, check air density if you are serious.
4. It is harder to drive a kart fast than a car. Stuff happens much quicker. You need to develop techniques for getting in and out. For not stalling the kart. For restarts.
5. Having to be push started sucks a little. Learning how to run start your kart is cool, but a little scary if you are old like me.

6. In the rain. I would rather stay home or autocross the tow vehicle.
7. You have to learn where to gas ras fuel and mix it with oil.