Bill Gates really is a genius. But I'd rather call him opportunistic than evil. He sent IBM to the guy who build the original OS and when he screwed up th deal and IBM re-contacted Gates, he just bought the ripoff company and signed a non-exclusive deal. When the Gary Kildall was finally given a chance to compete, he made his OS 6 times more expensive than DOS.
It's a really sad story that's almost like a Greek tragedy with an unfortunate death.
Bill Gates also compromised the quality of the eco-system for reaching critical mass in adoption. Steve Jobs had some major issues with this philosophy.