Calling him wasteful is odd too, sure he might miss big chances on off days and waste a lot in general. But with the stats he's been putting out over the last five years, he'd probably be a 40 goals/40 assist per season player if he wasn't "wasting" all those chances, wich would make him more productive than Ronaldo or Messi. Not very realistic to expect that.
And besides, all top players miss shiteloads of chances anyway, I see the likes of Muller, Robben, Bale or even Ronaldo miss sitters nearly every week. To me if anything, it's a good sign, because at least it means chances are created, something which has been one of our biggest problems since the Moyes days.