Easy mode is good. Simple.
People have different levels of skills, and many people haven't been playing games as long as I have, and many have played for longer. To expect all to have the same reflexes or skills is silly. I'd be happy (Play-wise), if they removed all the difficulties below the "Hard" one on FPS games. But if they did that to Total War, I'd be screwed. So acknowledging that some people don't play as well as we do is to acknowledge our own failings, and that we might need it at some point. Most of us would rather not be excluded from a game simply because we're not practiced enough. What if a new genre of game came, that no-one had talent for, that was ridiculously difficut? Would it be simply whining to be disappointed that we could not play because we weren't able to play on that difficulty? Of course not. It's simply silly to design something like that. Excluding deliberately obtuse titles like IWBTG, it's not the core concept, and changing the difficulty doesn't dilute that concept.
Variable difficulty lets each player choose what's enough to give them constant challenge. I'd never choose a difficulty I couldn't play, because hitting the wall and being unable to experience the content is 1) A waste of money. 2) Shows lazy design. If you can't graduate the difficulty so all can play it with their optimum level of resistance, then you're just bad at doing your job.
It's like at the gym. I might be able to put the Chest Press on 50kg. Some really skinny guy might come over later, and only can do 15kg. Some ridiculously buff guy might come over after him and put it on 80kg. We're all choosing our optimum level of resistance to give us constant effort. None of us is doing it wrong, and if the machine is designed well, everyone gets the same use out of it at different resistance levels.
EDIT:With the trend for content unlocks with progress, and the ability to buy progress with money, in games like Battlefield, Rocksmith, etc, it seems foolish to hitch up to the "Super hard games" bandwagon. Sooner or later, they can start releasing games which are too difficult to unlock the content for, forcing the player to buy into it. Far more insidious that DLC ever was.