Yes, or course they can (at least for me). Let us look at one of my favorite games of all time, Kingdom Hearts 2. Now this game is easy. Really, really easy. Even on the hardest difficulty, the game is still pretty much a cakewalk. Yet, I have played and beat the game at lest 4 times. The reason? I was not looking for a challenge. I was looking for fun, and this game has it in spades. The combat is great fun, the story is great, and the graphics are pretty. When I play the game, it makes me feel like a God, crushing entire armies beneath my key-blade. It was (and still is) fun to feel empowered.
Personally, I have never understood how hard games are better myself. I just do not see it. I would rather have an easy game than a hard game. That is not to say that hard games are bad, I just tend to prefer easy games.