How does the most important physicist of the last 30 years not have a nobel prize?
You're all filthy goyims, this thread is getting meshuggah. I am -NOT- Jewish, gosh, gosh.
He wrote an amazing dissertation out of grad school - the one where he compared the expansion of the universe to the time-reversed equivalent of a black hole. He basically conceptualized one of the leading problems in astrophysics at the time, and didn't win anything from it.
Hawking has little to nothing to do with String Theory. His famous black hole theories are obtained through quantization of normal general relativity. Because at low energies, non-renormalizable theories are acceptable.
Same reason Peter Higgs got the Nobel after LHC found evidenc of the boson he described 50 years earlier.
If someone detected Hawking radiation he would get a Nobel without a contest.