Sweeney did nothing wrong.
Sort of, but not really. Publishers did that but it wasn't as simple as that, it was more like figuring out a Venn diagram of features and abilities between platforms and build the game around what every platform could do. That means CPU limitations, what the proto-GPUs could do, memory and all that. So they make a core game then they start adding platform specific tweaks to graphics, the type of graphics that doesn't change how the game is played. That's why Sony in the PS2 era usually came out short on multiplat games while at the same time having exclusives that did some truly spectacular things.The simplest thing to do with multi-platform titles at that time would be to to base it around the PS2, then just copy paste on Xbox/GC. If you're lazy.