I think people are confused about what "dropping support" means. Dropping support does not mean, "you can't play the game on this platform anymore." Dropping support means "you can play up until a certain point, but after that expansions and client features added will ONLY be available for X and Y players. You will not have access to these features/gear/level cap increase/quests/etc."

It's not always hardware/software limitations that come into play. It can also be population that devs use to decide if they will drop support for a certain expansion/update. For example, the playerbase of FFXI utilizing PS2 outside of Japan is so small, there would be no financial gain to releasing an expansion for those people. If I recall, the latest expansion was not available to FFXI PS2 users outside of Japan for this very reason, and it was also the last expansion to be available to PS2 users in Japan. In essence, SE has "dropped support" for PS2 because now features will be limited for those who continue to play on that console.