LFR is casual content and so should be easy. it's the equivalent of "story mode" in a single player game, allows you to see the content and get an idea of what the challenges are like but without the frustration of difficulty. it's fair to argue that current LFR may be too easy, but then remember what LFR Molten Core was like. you couldn't ask for easier content tactics-wise but pretty much every LFR run in there was a chaotic mess of ninja-pulls, suicidal zerg attempts, arguing and frustration
there's no solution that will make everyone happy, but LFR is a neat compromise allowing those who just want to see the content to do so without clashing with those who want a genuine challenge