ALTTP was difficult, but so to was MM. I mean Stone Tower was pretty difficult if you didn't know what to do. Plus the game tries to trick you because you'll be thinking the item you get in Great Bay Temple is supposed to be used on the boss. A newcomer would be fooled. Wart guards the Ice Arrow, which does nothing to Gyorg. So MM screws with you too. I also like Stone Tower Temple's two guarded items. Plus the final boss is pretty hard and the internal clock system was pretty demanding. I mean, after three days (game days) you get game over. BUT, that does not take away from the game's fun level, it actually gave to it.
ALTTP was an innovation in Zelda history, but so was including two games in one cartridge. Four Swords was an innovation as well, controlling four links with three other friends. Anyway,
ALTTP is by no means easy. People think that just because there isn't anything of today in the game, that makes them too easy. I think that no game is too easy. Be it Zelda, Mario, Banjo, whatever, it can never be too easy.