When these software were rewritten, at that time developer are consider intelligent enough to understand Physics, mathematics etc..Now a days a Online Degree make Developers. The So called next generation of programming hide some low level optimization and developer often do not by pass them. They were written for Business application, but they use in game application. unlimited resources, operating system efficiency lost (as they suffer from same problem, as well as more security code is added to them that somewhere bottelneck it) are some other stuff that has effect on efficiency.