First I must say that I am not an expert in string theory so my understanding is minimal and therefore feel free to correct any misunderstandings I may have.
String theory is very popular among mathematicians and physicists nowdays. I can understand why mathematicians may be interested in it, since to us it's just another theory but I cannot understand why physicists are so interested in a theory that we have no evidence is the correct theory of quantum gravity.
Here are a few points about why string theory is a questionable theory of quantum gravity.
String theory hasn't managed to eliminate singularities. One of the reasons we want a theory of quantum gravity is to deal with singularities, but string theory not only doesn't resolve them, it even generalizes them to higher dimensions.
string theory hasn't made any prediction. In fact, as far as I know (please correct me if I am mistaken) string theory hasn't even been able to predict classical phenomena and I am not sure whether it's possible for string theory to make any prediction.
There is no experimental evidence of supersymmetry or even the existence of the graviton.
It cannot give general relativity as a classical limit. Many times I have heard of people claim that string theory gives Einstein's field equations in the classical limit but I have yet to see it in process, it can give rise to Einstein's field equations only for special cases but I haven't been able to find any proof that the theory of general relativity can be fully recovered from string theory (hopefully you can show me references to prove me wrong)
So I want to ask, why do physicists believe that string theory is the appropriate theory of quantum gravity?
What evidence do we have?
Is it just because it's the best we have, so we choose to work with what we've got?