Blizzard cleaned it all up. Their games were so good no one even bothered to compete. I spent countless hours playing starcraft and warcraft. The other games didn't have the same addictive elements.
Agreed, it's a huge reason. Blizzard is the Nintendo of the PC space. Developers have noted for ages that competing on Nintendo platforms meant you had to match their 1st party titles. Which are held to a higher standard than others and don't get the reviews they deserve. There are few true competitors to the Mario games, Smash Bros, Mario Party, and Mario Kart for the same reason most people don't want to be compared to Blizzard's efforts.
