GW's root problem is that it tries to appeal to both hardcore (PvP and expert PvE) players like us, and also to casuals. Casual players -- those with a few hours a week to play -- have no hope of H/Hing the campaigns. And if they get frustrated, they quit, and if they quit, they aren't buying new chapters, and that means ANet loses business.
And due to the lack of a monthly fee, GW has a strong appeal to casuals.
Honestly, I think ANet needs to make some parts of Normal Mode slightly easier for the casuals, and make Hard Mode and end-game content challenging (as opposed to just boring "bigger, faster" monsters) for the hard cores. That may be what they're trying to do... but it still needs a bit a tuning, especially on missions that create "roadblocks" for casuals -- like Gates of Madness, Aurora Glade, and such.