Think of it as planned obsolescence.

Eventually, you won't be able to get anything FFXI for the PS2 in the other regions. When Sony one day no longer deems it cost effective to support PS2 in the JP region, it too will go the way of the Dodo as a viable FFXI platform there as well (Sony has already slated this for review in 2015). Think of it this way... there is a reason i386, i486, P5, etc. systems left the market and Intel stopped producing the CPU's---better systems hit the markets and the CONSUMERS moved to the better platforms.

It is an inevitable change that IS GOING TO HAPPEN, whether you like it or not.