Originally Posted by
Volkai
Actually there is. The reason is the cost to manufacture and distribute an NA-region PS2 disc as compared against the potential profit of selling that disc.
Keep in mind the PS2 is region-locked so a JP disc would require a JP PS2 to use. Any NA PS2 install would require an NA-specific disc, so they can't just take the same JP PS2 disc they're already manufacturing, slap it in a new box, and ship it overseas.
You are correct, that is not a reason for exclusion. It also is unlikely to be why SE did what they did. (See above.)
That would be because of the different hardware the two systems contain. Only the first (and second?) generation of PS3 could run PS2 games at all, and that's because they basically shoved a PS2 inside of the PS3 box.
So don't quit. You have several options:
1) Continue playing on PS2 (or on a PS3 with PS2 backwards compatibility) without the Seekers of Adoulin expansion.
2) If you have or acquire a JP-region PS2 (or JP-region PS3 with PS2 backwards compatibility), obtain a JP-region Seekers of Adoulin install disc, and continue playing on PS2/PS3.
3) Switch to PC. (Acquiring an FFXI-capable PC if you do not already have one.)
4) Switch to XBox. (Acquiring an XBox 360 with Hard Drive if you do not already have one.)
5) Quit.
Personally, I would recommend option 3 or 4, as those are probably cheaper than option 2's importing a JP-region PS2/3 and expansion disc, and don't limit/remove your gameplay as options 1 and 5 do... but the choice is yours, and these are the options I see being open to you with the reality of the situation being what it currently is.