Seriously, I know this question has been asked thousands of times, but why is it called The Legend of Zelda when she's not the main character? She doesn't even do much in most games.

It's not like she's the one scouring Hyrule for ancient McGuffins and eventually killing Ganondorf.

and why is Nathan Drake using a map in UNCHARTED?

Are you trying to make a point here?

Why is it a FABLE if it is a tale about humans?

Yes...

It shows how humble link is.. and because the adventure of Link sounds pretty terrible

In the original game, the hero is supposed to be no one special. Zelda is the princess and Ganon is the ultimate evil. Who is Link? A shmuck. He's a nobody that saves the land while overcoming impossible odds. That is why the story is cool. And it is also why the Legend is about Zelda.

The original concept of the game has greatly changed over the years.

I fail to see it. *revs chainsaw* So tell me what it is!!

How can you have 15 FINAL Fantasies?

Why would he.
The places he visits are uncharted, a map would be useless.