I agree. I think multiplayer in these Nintendo games is just as fun as everyone says it is. I myself was skeptical at first because I'm a bit apprehensive when it comes to cute games but after I get over the cute designs I realize the gameplay is very complex and well worth the money.Mario Kart is definitely a game that is best played with other human beings rather than solely against CPUs. That doesn't make the game overrated, though.
Mario Kart is one of the few games that I think consistently lives up to the hype surrounding it. It might be frustrating at times, and it's certainly more fun with friends, but overall, the series always delivers with consistent, high-quality, fun, and unique games that tend to last for quite a while. I would say it's always well worth the price, and the feature-rich DLC that is coming seems to reinforce this. I've never really been disappointed by a Mario Kart game as a whole. Even if I do think that some are better than others, I think that even the "worst" Mario Kart games can easily be played for a long time without disappointment.