Look the Gamecube was more "successful" than the xbox and right now Ps3 and 360 because it brought in more money than any of these consoles did. It made a profit. PS3 and 360 are starting to profit but they will need to increase by a huge amount just to offset the losses already made. The Wii is the most successful console of all time not because its the one which is most bought but because the profit made by Nintendo because of it. DS as well. They profit on the machines as well as the games.
MS and Sony require large sums of games to be sold to offset the cost of the console which therefore reduces their profitability.
In the end if a company sells 100m consoles but doesn't profit from its endevours then it was a waste in the eyes of shareholders. You need to profit from it and right now Nintendo is the one who is laughing all the way to the bank.
