The GameCube for whatever reason has a pretty insane tie ratio with software.
For example at 22 million LTD it sold more software than the 3DS has with 50+ million users.
So that probably didn't hurt. That is kind of the reason you do want third party support even if its garbage, as a platform maker it's literally printing money. You charge $10 a copy for every game, doesn't matter if its some crap Barbie game destined for the bottom of a discount bin, you get $10 for every copy of every game made ... that's just easy money.







