[InclinedPlane]

Modern software is a lot more complex than it used to be, with vastly more functionality. In terms of games, as just one example, the difference between the '80s and today is extreme. There's more coding and graphics work in just a tiny little throwaway piece of a world in modern games than there were in many '80s games.

Also, the level of bugs that are tolerable if you have no method for patching are different than if you do. Super Mario World, for example, has a number of bugs that are now quite well known, but those bugs are in general small enough to not warrant recalling the product so we still tend to think of the game as "perfect".