You make some very interesting points about the similar sales figures on platforms with very different install bases. Though you have quoted select examples and these things do sometimes change over time.
I think there are SOME Nintendo franchises that are already saturated in popularity (I doubt something like Pokemon would sell much more than it currently does). But what about Fire Emblem, Xenoblade, Metroid? Those would almost certainly increase in popularity several times over if they were multiplatform. Xenoblade Chronicles is perhaps the finest game ever made that didn't sell 1 million copies.







