It is possible you bolded the wrong part, depending on how you view the sentence:
No, it's pretty clear he says "you have to start with the PS3" the conversion is from the PS3 start to the other platforms, PC or 360.
You see the PS3 has the Cell Processor and a nVidia RSX GPU based on the 7800GTX. The Cell Processor has a PPE and 7 SPEs(really 8 but due to initial production yields 1 is disabled to allow more processors to be available). The PPE is basically your standard CPU core, the SPEs are specialized Cores that handle specific types of calculations very quickly. So the Cell has 8 cores.
Now ask yourself this question,
Is it easier to start with a complex system and simplify it, or is it easier to start with a simple system and add complexity.
In general it is easier to take a complex system and simplify than add complexity to something simple.
I've read a lot of articles on PS3 development, If developers start designing for the Cell Processor they break things up more and assign them to the SPEs better. You see the nVidia RSX is a Direct3d 9.x capable GPU so it can do things in OpenGL at about the level of a Direct3d 9.x card, but you can use one of the SPEs to make up the difference and have it handle a specific area the RSX is lacking like surface reflections on water and get the game to look like the level of Direct3d 10.
If you develop for PC or 360 then port to the PS3 you have a lot less multi-threaded code, you have to then go back and try to break things apart and it is time consuming and buggy. That's why you see articles about a PS3 game having bad frame rates compared to the 360 version at a gameshow. The PS3 version the developer is basically cramming everything through the PPE and the GPU and didn't segment things out to the SPEs to even out the workload.
The way Developers now work is the Big-Dogs develop their own in-house development environment. PC workstations and server, common assets, all the same models, textures, sounds, animations and so forth. They keep is as platform agnostic as possible and then compile it out to the target platform.
A good example is this: http://software.intel.com/en-us/videos/gdc09-multiplatfom-game-development-with-crytek39s-cryengine-3/
the PS3 and 360 are developer systems that can be tied into the PC workstation, so the build can be pushed to them in realtime.
In a way it is almost irrelevant, because they are compiling out for each target platform from a more generalized agnostic codebase than the way things were done for FFXI. FFXI was built as a PS2 game, FFXIV is a multi-platform title, there is a world of difference between porting and compiling. Edited, Sep 11th 2009 11:40am by kgav