Perhaps this idea may have been said already, but I really think all raids in this game should have multiple difficulty levels similar to primal fights (Normal, Hard, Extreme). Normal would be fairly easy, but does not drop loot. Hard would be the intended difficulty, and drop loot normally. Extreme would be much more difficult than intended, but drops better or more loot.

That way, casual players who only want to clear them for the story/achievements can do so, while the more hardcore players can get their dose of challenge. This may also inspire the casual players to improve their skills so they can clear the higher difficulties and get the awesome loot.