pcsx2 is like a translator...it acts as a translator between console languge<there is no specific language for them...but lets just assume in this case>....and the language which computer can understand.
console language is diffrent becasue parts used in console are diffrent<it is used specifically for gmaing>where as pc is used for many things and hence its parts are diffrent.
if you can use a translator from a->b....it doesnt imply that you can use it from b->a
again ..........windows and linux are diffrent........why??......they are like two diffrent languages used to complete the same thing.for each thing we need a special progrma that can translate the so called console language to it.
basically you cant use pcsx2 in the ps3 until its modified for it
and you can use windows pcsx2 on linux as they are diffrent