Only partly true, afaics. Trent bridge was the only real spinners' track he played on last summer, so the rest of time he was having to cope with conditions that weren't over-helpful. At Old Trafford, although you could argue that he benefited from Harmison's efforts in the 1st innings, the reverse was true in the 2nd innings. From memory, he had two poor tests last summer - the Oval and one of the Lord's tests (sorry, can't remember which one). Other than that, he did well.
Going onto his strike rate, it hasn't helped him playing all his tests either against Asian sides who are generally pretty good against the slower stuff, or against the best side in the world. That doesn't make him the finished article, or change the fact that he still has a lot to prove to live up to some of the hype, but he deserves more credit than you're giving him, imho.