Backward compatibility is a stop-gap measure during a modern console's early years that is removed in later iterations of the hardware when the platform has a self-sustaining number of games.
See: Playstation 2, Gameboy Advance, Nintendo DS, Playstation 3, Xbox 360, Nintendo 3DS.
In the early months and years of a new console's life, there is obviously a small amount of games. Allowing a user to enjoy their older games on the new console can - and does - alleviate the pain of waiting for new releases to arrive.
It's the practice of "keeping them busy" until the console is actually worth purchasing for it's library of games.
Later in the console's life, no one cares about the previous generation's titles as by now the current generation has been established: they don't want you to play older games you've already bought, they want you to pay for new games that have just been released.
You can argue about these facts and dress them up anyway you so chose: backward compatibility is used to sweeten the deal of a new release console that has bugger all newly developed and worthwhile software. When it's no longer required, they remove the deal sweetener, and begin selling those same games back to you at a premium while changing nothing.
See: Playstation 2, Gameboy Advance, Nintendo DS, Playstation 3, Xbox 360, Nintendo 3DS.
In the early months and years of a new console's life, there is obviously a small amount of games. Allowing a user to enjoy their older games on the new console can - and does - alleviate the pain of waiting for new releases to arrive.
It's the practice of "keeping them busy" until the console is actually worth purchasing for it's library of games.
Later in the console's life, no one cares about the previous generation's titles as by now the current generation has been established: they don't want you to play older games you've already bought, they want you to pay for new games that have just been released.
You can argue about these facts and dress them up anyway you so chose: backward compatibility is used to sweeten the deal of a new release console that has bugger all newly developed and worthwhile software. When it's no longer required, they remove the deal sweetener, and begin selling those same games back to you at a premium while changing nothing.