Re: "Nvidia's dominance"?
"Eh? Last time I checked, Intel had ~70% of the total graphics market."
Well, yeah, since it seems most if not all Intel based PCs are sold with onboard graphics these days. The vast majority of people either can't upgrade (corporate purchases) or don't know it's an option. Why would Joe Average spend extra on a GFX card when their shiny new PC came with one built in with DisplayPort/HDMI/DVI sockets already in place? The only people buying GFX cards are those who have a specific need.
It's the Microsoft business model.