"Prepare to die." Dark souls sold to the average player based on "being hard". Many youtube video and reviews and community discussions each pitched Dark Souls as a challenge, but with the distinction as being a fair one. Dark Souls with an easy mode would lose a ton of community appeal and many sales if it were to add an easy mode.
That said, I'd like cheat codes or a way to make it clear there's an easy mode, but it's not the intended experience - for those looking to avoid the challenges. More importantly, NG++++ endless cycle acts as difficulty options for increasing the diffficulty, so I don't feel the need for difficulty options there.
Balance in souls games is bad enough, I'd rather they focus their dev time fine tuning a single difficulty, rather than having multiple to pick from the start.