I'm curious why you call the string theory a debacle.
From what I followed, the debacle was rather with supersymmetry. And even though, the research in this domain stimulated the development of new mathematical tools.
Finally, as with all failed research, it would have been pretty hard to rule it out without trying to search it before, so this negative result is as much positive result in favor of rival theories.
(maybe super-asymmetry ;)