Mapping, programmability and scalability of problems for quantum speed-up

This paper explores the reasons as to why the quantum paradigm is not so easy to extend to all of the classical computational algorithms. We also explain the failure of programmability and scalability in quantum speed-up. Due to the presence of quantum entropy, quantum algorithm cannot obviate the curse of dimensionality encountered in solving many complex numerical and optimization problems. Finally, the stringent condition that quantum computers have to be interaction-free, leave them with little versatility and practical utility.