Actually, it's a lady boner for dragons. I'm not even sure if that's a joke.
And that lunacy is part of the appeal! Kaiba is legendary, and his turbo autismo is kinda the flashpoint of the whole Yugioh universe, from the card game going worldwide, to the dissolution of the fabric between the different planes of existence, all the way to space.
And Kaiba wasn't exactly spoiled, his adoptive father kinda hated his guts