The RNG gods seem to hate me very much for some reason. I've been missing Will-O-Wisps and Hydro Pumps on my opponents time after time yet they never miss Dragon Rush (lol what?), Fire Blast, Stone Edge, and Focus Blast. Not to mention that I've been on the receiving end of countless critical hits recently and I can't remember the last time I landed one. I think I just need a break from this game and its "Random" Number Generator.
I don't give a FAQ. Applei 3DS: 3737-9612-2086---PM me if you want a free 5IV Goomy Egg~
I am not completely sure why you are having such misfortunes, but you aren't alone. Copious players are encountering the same issue. I believe this sixth generation may just be more strict on hit chance (accuracy). I have seen many Wi-Fi Link battles, and the attack Stone Edge is being renamed "Miss Edge", "Stone Miss", and even "Miss miss" by the players that unfortunately miss.
If it bothers you, to the point that you aren't enjoying the game, I would recommend that you go to a Move Trainer and teach your Pokemon a more accurate attack, or breed for another Pokemon that you can teach a whole new move set to.