So you care only about the story. But LFR is too easy. Why do you care if it's too easy if you only care about the story and "char progression"? If you do care about the difficulty, don't do LFR, do only Flex if that's hard enough for you, or normal.
^ This. Cross-realm may have its flaws, but it makes it very easy to find like-minded individuals to play the game the way you want to play it. LFR, RDF, etc etc they're all TOOLS, not requirements or absolutely necessary paths.
Leveling's too easy? Find a way to make it more interesting and hard:
http://www.wowironman.com/rules
There are so many games which have "easy" difficulties that let you see the content you paid for if you're not a great player or don't care much about getting better/learning. That's what LFR, for instance is. You don't have to do it if you find it too easy.
And there is a LOT more content than dungeons and raids, some of it time consuming, if you want it
I do agree leveling/questing and dungeons should be harder, or at least start easy and slowly become harder. But...
WoW hasn't become easier. WoW has become more accessible, to a wider array of player-type. The difficulty now is in actually having to get better at playing your class almost perfectly and being executing boss tactics flawlessly, for those who want that kind of difficulty, instead of being only in the ammount of time you can dedicate to the game.