I suppose. I don't think that's necessarily true in every case though.
I think bosses should be designed so first you have to figure out how to hurt them, then they're still a challenge because of their design. For Zelda, but also for video games in general.
Pathetically easy. I had someone show me how to beat him before I fought him, so I beat him in one shot, although I had a little trouble as I sucked at video games back then.
But I don't think I would have had as much trouble as I did against Phantom Ganon.
All in all, a pretty weak final...