The Nintendo Wii requires zero extra hardware to achieve backwards compatibility - the CPU is natively compatible as it is, all that changes is the stepping. The PS3 required additional chips to achieve PC - practically putting a PS2 inside the PS3 - it caused additional costs, didn't work very well and was eventually dropped. If anything, Nintendo dropped Backwards Compatibility only not to have to put Gamecube ports on their systems. That's literally the only expense required. At the end of the day, both consoles were stripped of Backwards Compatibility, so you don't have a point.