I agree the sales were close, but I think the narrative/momentum was very different for the two. That was Microsoft's first console. They started with nothing,

I agree the sales were close, but I think the narrative/momentum was very different for the two. That was Microsoft's first console. They started with nothing, and by the end of the generation had sold more than Nintendo and established critical IPs and an online service for the next generation. Nintendo, at the time, felt very backed into a corner - which of course gave us the Wii that shattered all expectations.