Woit's arguing that the study of string theory should be abandoned because it fails to make correct predictions about TeV scale particle physics.
He's wrong in two ways.
First, he's wrong to single out string theory for this particular failing. The Standard Model has stood for 40 years. Many extensions have been proposed, some string, some not. Not one has made a correct prediction. The stringy extensions are more complicated than some other models, but they're also better behaved in some important ways. Most Standard Model extensions are just more of the same dysfunctional effective field theory nonsense. At least strings is finite and couples to gravity.
Second, he's wrong that making these predictions is the correct metric for judging the work of the string theorists. The people I know who study strings study it because they see it as the best approach to learning new things about quantum field theory and quantum gravity.
These are extremely hard subjects, and no approach has been very fruitful. But string theory has been relatively successful as a source of new ideas. It's given us new classes of standard model extensions, calculable examples of confinement, new QFTs, calculable examples of holography and black hole radiation. No other approach can say as much, which is why string theorists are a large subpopulation of high energy theorists.