Early PCs were massively disadvantaged because of the wide range of hardware their software had to support. The Amiga only had one architecture and so supporting them didn't take much RAM or CPU power. Now things have changed and custom hardware is stone dead, this had turned to an advantage for PCs and a massive disadvantage for Amigas.
It didn't change one thing though: PC software didn't have to be efficient because most people had the hardware. That had been totally blown out of proportion now, and the Windows (and Linux) coding ethic is, "Who cares if it's slow and big? Just buy new hardware."
