Games drive install base, not vice versa, you don't buy games to play hardware, you buy hardware to play games
If the games cannot drive the same sales and hardware as their predecessors, they aren't as well recieved.
A 2D Mario game that developed exciting new worlds to explore (this is what 3 and world did), if they devoted the same resources they used on galaxy, that would have been possible, a Mario kart that surpassed the Wii and DS versions. Those would have driven sales.
Basically they needed to surpass what they offered on the DS, they didn't do that, in fact they fell well short of even that level







