You misunderstand, first: it is not the case that new observations about the world forced the changes. Instead, it is mostly observations about the internal pro

You misunderstand, first: it is not the case that new observations about the world forced the changes. Instead, it is mostly observations about the internal properties of string theory which has forced modifications. After it was proposed as a self-consistent theory of quantum gravity it was realized it wasn't self-consisten because it had ghosts, which was then fixed by adding 22 dimensions. But this is a problem because that's not how many dimensions the world has so they solved it by compactification that folds all the extra dimensions tiny so they don't bother us. But then it turns out that there is no particular reason to fold just so so that we get the world we live in. And now they are trying to find a way to make it so its natural that the folding happens just so that we get the world we live in. Secondly, and most importantly, while it is true that some models get revised whenever there is more data, those are poor models. Good models agree with all the data and don't need modification. (The best models agree with most of the data, but sometimes don't so that the scientist gets a mystery to solve!) Realistically this stage takes a while to happen, and proponents of string theory argue that they right now have a models that is going to be great one day, but right now needs a bit of tinkering. What critics say is that string theory has been in the "tinkering" stage for around 50 years now and maybe we should try other ideas a bit more. Finally, I don't think Sabine likes being refereed to as a "he" and rather have that pronoun used to describe the father of her children rather than herself.