Why is subatomic decay probalistic?
The probabilities can derived in MWI using work done by Everett and DeWitt in the '50s and by Deutsch and Wallace in 2007.
quantum computing is based on wishful thinking and ignorance.
Actually, proof of concept experiments have already been done for both Shor's algorithm as well as Grover's algorithm.
It's later than you think, the joint Russian-American space mission has already begun.