The reason people don't use it is because it took SE took way too long to fix the previous interface. People got tired of asking for it and eventually just forgot about it. I'd bet any amount of gil if it was addressed way back when it should have been you would see many more people using it today.

The shortened leveling curve plays a role in this as well. Most people are done leveling battle classes. There's just not as many newish players as there was when the game first launched (when they should have addressed this issue).

The only thing that will make the search feature useful now is a huge influx of new players.