I'm going to go with people not being able to be happy. After all, the first two episodes were criticized for being too packed and complicated. This pirate episode was criticized for being too simple and boring. Is there a happy medium? Yes. Is it realistic for all episodes to be within such a narrow range? I'm going to say no.
There's nothing wrong with a simple episode but cripes, at least make it consistent with the show! This episode was an embarrassment. The fresh alien "bogeys" gag might have been funny if they hadn't come from aliens that supposedly decayed ages ago! Do they really think the audience is that stupid? The TARDIS sickbay was used last year, the Doctor said he could save an almost dead Amy if he had the time, yet he sits there stupidly while Amy attempts CPR? For that matter, how was Rory talking if he had water in his lungs? Or did the water somehow magically get back in there once he was removed from the machine? There's a vast difference between simple and badly written. So many DUMB things in this episode that make me wonder if the writer had ever watched a minute of Doctor Who in his life. Or how he even got to be a professional writer for that matter. Anyone proofreading that script should have picked it apart. I'll take a packed and complicated Moffat written episode any day.