There's a good reason why most people who specialize in quantum gravity work in string theory: violating any axioms of string theory leads to theories which are

There's a good reason why most people who specialize in quantum gravity work in string theory: violating any axioms of string theory leads to theories which are self-evidently inconsistent with themselves and/or experiment. It's worth spending time trying to understand why, but unfortunately a lot of air is sucked out of the room by Woit's petulant negativity. It makes for fun podcasts but I'm glad researchers are willing to actually sit and think about the consequences of physics that doesn't match our intution, even when it's hard. And indeed this quote misses the point. The point is that there aren't "additional" effective theories of gravity that are self-consistent but couldn't be explained by string theory. This isn't a smoking gun that string theory is correct, but if the opposite were true, it would have suggested that string theory was missing something. So it's incorrect to conclude from this evidence that string theory is "consistent with everything"; it's merely consistent with the range of things that are consistent, and no more and no less. (Suspicious! But not conclusive.) One can complain that this isn't predictive, and indeed if you want to look for predictive power you look at other physical quantities. String theory makes very precise and unique predictions for the way that e.g. gravitons scatter off each other. The fact that humans don't (yet) have the ability to do such experiments is regrettable from a fundamental physics perspective, but it's a problem with humans, not string theory. So string theory continues to be a demonstrably self-consistent, (in principle) falsifiable, and stunningly beautiful theory--and dismissing it out of hand is a tragically common mistake.