If you cant picture Link setteling down with Malon on a ranch, then let me ask you this, can you picture Link as a King? I dont realy see link sitting on a thrown all day, seriously, what leader would Link be, would he rule his countrie from behind a desk or would he just laze about in comfort while zelda and/nobels do all the work.

Besides, Zelda might have an older brother (or sister for that matter) Link might not become king because of that.