I see the words "incredibly difficult" yet they translate in my head to "long and tedious grind with shiny at the end"
There is a huge difference between tedious and difficult. Getting a legendary in GW2 was long and tedious but it wasn't difficult (nor was it very rewarding). Unlocking the Kid in Super Meat Boy only takes a few hours but it is incredibly difficult (and very rewarding)
Very little requires technical skill in an MMO... so this comment is mostly irrelevant to XIV. Not to say I don't agree with you, because I do, but the game mechanics don't allow for incredibly difficult and short.
Why not? Mind you, difficulty tends to be relative, both on a personal level and your chosen class for the encounter, but I'm in general agreement with KG that when the squeaky hardcore player wheel makes itself known, it usually means grind, grind, grind, grind, and grind some more. Add some RNG and lockouts for added frustration. Perhaps people who hope for the Dark Souls MMO equivalent will be left forever wanting, as such is indeed a niche preference. Doubly so with a monthly fee involved.
Though, I feel some of this problem stems from nomenclature. When people sling terms like Epic or Legendary around, they're obviously hoping for the context of supreme or ultimate. Given the nature of MMOs to evolve, with this cap increases and new gear to follow, it's perhaps better for devs to avoid this kind of distinction. Otherwise, you get situations like in XI where people are pissed about their RMEs being weaker than Delve weapons now. As well, I've seen the WoW crowd ***** about their gear getting replaced by quest greens when that time rolls around. It simply is a case of never being able to please everyone.
Either way, I'm of the mind XIV is the hardest MMO I've really played compared to Rift, Aion, Tera, GW2, or even XI. Some of this is due to everything still being new for everyone. Sometimes it's just being paired with bad players in dungeons. Hardcores may laugh at that sentiment or gloat (and lie) about their own experiences, but regardless of which side you're on, there are learning curves.