Allow me to bring in the counterpoint. As a high-school senior, I go against the "kids only" generalization and watch this show. But for what reason?
You'd think that a simple saturday morning kids show wouldn't interest me, especially when its description fits a mixture of Pokemon, Dragonball Z, and the ever so "geeky" Magic: The Gathering. (Don't get me wrong, I play Magic too! Sparingly...). Seeing as how Dragonball Z is basically a lot of muscles and flashes and yelling/grunting sounds (even in the Japanese comic books), and how Pokemon in the U.S. is just horrible, it at first doesn't seem apparent on why I like Yu-Gi-Oh! so much.
Well it's really the structure and suspense of the show. Although it has its "Pokemon moments," such as blatent verbalization of the episode's moral, The background setup and fight scenes are worth it. Yu-Gi-Oh keeps you on your toes, slowly incorporating you to try and find out more. Then you become hooked, like myself, owning 4.5+gigabytes worth of Yu-Gi-Oh! videos. Just experiencing the amazing turn-arounds and combos intrigues the mind of an ex-Magic player.
Beyond the television show aimed at children, the fighting engine is simple, yet very capable. Someone at the Bandai or Konami corporations thought pretty hard about the mechanics of the game. Actually, now that I look back at Episode 1 Season 1 of the Japanese version, (Season 1 in Japan was cut from the US version by 4Kids Entertainment; Season 1 in the US is actually Season 2) I realize that there is a plentiful amount of swearing, and much larger breast sizes in general among the female characters. Isn't that how it always is in Japanimations?
Just watching the show almost makes me believe in the heart of the cards, hehe. It's that strange tingle of hope, courage, struggle for power, friendship, and honor you feel after engulfing into the YuGiOh universe. I know three very unlikely people that have been sucked into this addiction, one of them is myself, of course. Try it, you may like it.