Why should anyone take a nonphysicist seriously on such a fundamental physics issue?
String theory is math, not physics.... and it will remain so at least until it stops being abstract and starts making falsifiable predictions about the REAL world. To quote Einstein(?)
"Mathematics studies the relation between concepts. Physics studies that relation between concepts and reality."
Calling him a nonphysicist isn't correct. Woit's just not employed as a physics professor. Instead he's got a nontenured math post at Columbia. Given the number of tenured physics jobs available versus the number of graduates, it's not exactly surprising to see a physicist who isn't a "Professor."
"Not Even Wrong" is a good book, but a little dry. Lee Smolin's "The Trouble With Physics" is a much more enjoyable read and was much more engaging. But they both deliver a strong case against String Theory.
String theory is math, not physics.... and it will remain so at least until it stops being abstract and starts making falsifiable predictions about the REAL world. To quote Einstein(?)
"Mathematics studies the relation between concepts. Physics studies that relation between concepts and reality."