Heh, cute example, but even being a technologist, I see the business reasoning here. If the logic of a program was described once, why does it need to be re-don

Heh, cute example, but even being a technologist, I see the business reasoning here. If the logic of a program was described once, why does it need to be re-done when the next fancy language comes out? Why can't all languages/systems be backwards compatible?