I don't think people find it a problem nowadays to find what they are looking for. For Voidwatch they just do massive shouts and generally spots will be filled fairly quickly. Abyssea party depend on what time of the day, on busy time, tons of people waiting with their flags up at worm party camp, you never run out of people to invite. Seal farm usually done with LS or your buddy, but then random shout still works too. Magian trials are done the same way, via random shout or you just go to the zone and search and ask them to team up - can also seek with comments. Skill ups party usually done solo anyway in abyssea, the loner who do it in GoV usually do not mind teaming up. So you see, there is hardly any need for auto finder. But if they are going to do it, they should do it like how WoW did theirs, pooling people across server for an instanced dungeon.