@Vetusomaru, Developers found it too hard to develop for, lack of proper documentation and was a lot more advanced. Not to mention that the Original Xbox was based on the Windows kernel and that it used DirectX, meaning it was just as easy to port PC games and optimize it for the console.
Inferior to the Xbox? yes most definitely, Gamecube, eh, only in terms of graphics. Still stronger than the Dreamcast, both the Gamecube and PS2 are,
hardware-wise
on an unrelated note, Sony was retarded: they had the perfect success formula with Playstation 1 (cheap console at launch, easily to make games at, diversity of titles) and instead of keeping the formula at later Playstation consoles they fucked it up. especially with PS3 and PS5.
If you have a ROM file that's calling to hardware that's part of the cartridge itself, that makes it tricky for an emulator since it has to do the console and any additional thing that the developer shoved in the cartridge too. Luckily a lot of that was standard.
@K3Nv2, Sony wanted to compete with HD-DVD and the Xbox 360, so they made the price of the console less than what it was advertised for. And because consumer players were expensive, some people bought one just so they can watch their movies... just like the PS2 as a cheap DVD player (well, depends on how you look at it for the price).
@anotherthing, And some Game Boy games that had extra SGB features, one example is Space Invaders with a modified version of Space Invaders for the SNES.
Kind of lame that the very last console that is likely to ever have a cartridge slot that can add hardware to the system is the DS Lite due to the Slot 2.