The probabilities spawned QM, not the reverse. The modern interpretation of QM is a reification of those probabilities - an insistence that they aren't the results of a process, but are just probabilities, irreduceably.
And it's not just like people found these probabilities and then decided to stop trying to explain things and said "what if these are just how physics worked". Instead, people found that any attempts at removing the probabilities (through local hidden variable theories) ended in contradictions, and then accepted that they must be fundamental.
